Luminous Landscape Forum

Equipment & Techniques => Medium Format / Film / Digital Backs – and Large Sensor Photography => Topic started by: Paul2660 on February 12, 2008, 04:25:43 pm

Title: Mamiya 28mm Lens filter question
Post by: Paul2660 on February 12, 2008, 04:25:43 pm
Can anyone who has this lens elaborate on what filters are available for it?  I understand it takes a 42mm gel style, but haven't been able to find many companies that make a 42mm gel.  

I am interested mainly in a ND filter, but also would be interested in any type of polarizer that would work.

Thanks
Paul C
Title: Mamiya 28mm Lens filter question
Post by: Don Libby on February 12, 2008, 05:12:29 pm
Paul

I have a 28 which I truly love.  I used for the first time last December at the South Rim of the Grand Canyon and never felt a need for a filter.  I just returned from Big Sur and Carmel and would have loved having a filter there.  I did a little research just after getting the lens and saw that no pre-cut filters were available.  I ordered a gel filter from B&H and attempted to cut it down to size.  The glaring problem I see with this lens is the filter system - frankly it sucks!  I'm experimenting with holding one of my Cokin filters up to the sunshade.  This may work if they are large enough - I might also have to tape up the shade so as to eliminate stray light.  

I'd like to hear from other who have this lens.

don
Title: Mamiya 28mm Lens filter question
Post by: HarperPhotos on February 14, 2008, 02:13:19 pm
Gidday,

This could work using a Lee 4"x4" filter and holding it on with BluTak.

Not the prettiest solution but it works.

http://www.morco.uk.com/latest/leepol.htm (http://www.morco.uk.com/latest/leepol.htm)

Cheers

Simon
Title: Mamiya 28mm Lens filter question
Post by: Don Libby on February 14, 2008, 04:50:33 pm
Quote
Gidday,

This could work using a Lee 4"x4" filter and holding it on with BluTak.

Not the prettiest solution but it works.

http://www.morco.uk.com/latest/leepol.htm (http://www.morco.uk.com/latest/leepol.htm)

Cheers

Simon
[a href=\"index.php?act=findpost&pid=174894\"][{POST_SNAPBACK}][/a]

Simon

You beat me to it!  After returning from Big Sur I thought the very same solution even going to Home Depot and picking up a roll of blue "painters" tape.  I tried it once using a cokin filter and think it'll work.  Agree that it might not be the prettiest solution but then neither is the guy behind the lens!  

Cheers!

don
Title: Mamiya 28mm Lens filter question
Post by: ternst on March 05, 2008, 10:16:14 am
Did any of you guys come up with a solution to using a polarizer on the Mamiya 28mm? Will the large Cokin ones work, or the Lee? I don't mind taping one of their holders to the front of the lens if I would be able to just drop in a polarizer when needed - or would I have to tape it each time the filter is needed? I also don't really mind holding a polarizer in front of the lens without taping it on, although being able to stick it into a taped-on holder would be better. I don't have this lens yet so can't measure, but what size filter would I need to cover the entire front element - would a 105mm do it? I don't use anything but a polarizer so don't need any others (like the 4 x 4's).

THANKS for your thoughts!

Tim Ernst in Arkansas
http://www.BuffaloRiverGallery.com (http://www.BuffaloRiverGallery.com)
Title: Mamiya 28mm Lens filter question
Post by: clawery on March 05, 2008, 12:33:17 pm
I'm not sure if this is a perfect solution, but wanted to pass this along.  Take a look at teh B+W 105mm Kaeseman Linear Polarizer Extra Wide Glass.  It has a filter factor approx. +1.3 stops.
The part # is 65-062129.

Chris Lawery
Sales Manager
Capture Integration, Phase One Dealer of the Year (http://www.captureintegration.com)

877-217-9870 | National
404-234-5195 | Cell  
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Title: Mamiya 28mm Lens filter question
Post by: ternst on March 05, 2008, 12:51:18 pm
Thanks Chris. I've been looking at that one and the 112mm filter as well. Do you know if that 105mm will cover the entire angle of this lens? I still would prefer a method of taping a Lee or Cokin holder to the lens and then just adding a rotating filter when needed - hum, I wonder if you could somehow "crop" one of these normal polarizers into one of the Lee or Cokin holders? I have one of the big Cokin holders and filters sitting around here somewhere but not the lens...
Title: Mamiya 28mm Lens filter question
Post by: clawery on March 05, 2008, 01:35:09 pm
I'm not sure if this is a perfect solution, but wanted to pass this along.  Take a look at teh B+W 105mm Kaeseman Linear Polarizer Extra Wide Glass.  It has a filter factor approx. +1.3 stops.
The part # is 65-062129.

Chris Lawery
Sales Manager
Capture Integration, Phase One Dealer of the Year (http://www.captureintegration.com)

877-217-9870 | National
404-234-5195 | Cell  
Sign up for our Newsletter (http://visitor.constantcontact.com/email.jsp?m=1101868815210&p=oi) | Read Our Latest Newsletter (http://www.captureintegration.com/our-company/newsletters/)

I don't have one of the polarizers in stock, so I'm not sure if it will cover the 28mm completely.

Chris Lawery
Sales Manager
Capture Integration, Phase One Dealer of the Year (http://www.captureintegration.com)

877-217-9870 | National
404-234-5195 | Cell  
Sign up for our Newsletter (http://visitor.constantcontact.com/email.jsp?m=1101868815210&p=oi) | Read Our Latest Newsletter (http://www.captureintegration.com/our-company/newsletters/)
Title: Mamiya 28mm Lens filter question
Post by: Bill Caulfeild-Browne on March 05, 2008, 08:44:05 pm
Quote
The inside diameter of the petal lens shade is about 87 mm. The inside diameter of the lens cap which goes around the shade is 90 mm. One possibility would be buy a spare lens cap, cut out all but the ring that grips the shade, and tape a 4 inch gel to it. Not elegant but cheap!

I've done this in the past with a 15 mm Leica lens and it worked for years.

Bill





Can anyone who has this lens elaborate on what filters are available for it?  I understand it takes a 42mm gel style, but haven't been able to find many companies that make a 42mm gel. 

I am interested mainly in a ND filter, but also would be interested in any type of polarizer that would work.

Thanks
Paul C
[a href=\"index.php?act=findpost&pid=174334\"][{POST_SNAPBACK}][/a]
Title: Mamiya 28mm Lens filter question
Post by: ternst on March 05, 2008, 10:24:54 pm
Thanks for those measurements - that helps. However that would not be a cheap way to get off - have you priced one of the spare lens caps? That would probably work just fine for a gel but I'm talking about a polarizer. I got a used 112mm B+W that I'm just going to hold in front of the lens for now until I can find a more elegant solution. If anyone has figured it out I would love to hear about it...
Title: Mamiya 28mm Lens filter question
Post by: Don Libby on March 05, 2008, 10:29:42 pm
"The inside diameter of the petal lens shade is about 87 mm. The inside diameter of the lens cap which goes around the shade is 90 mm. One possibility would be buy a spare lens cap, cut out all but the ring that grips the shade, and tape a 4 inch gel to it. Not elegant but cheap!"




Very interesting!  Just checked B&H and the lens cap is $31.00 and is a special order.  On the surface this sounds like a very simple solution – being cheap I’m going to look around for other light weight cheaper materials that will do the same thing.  Either case I think we might be on to something here.


don

Just checked Cokin thinking I had remembered them having a special adapter.  The adapter is for lens with damaged threads and fits on the outside – that’s the good news and bad news is that it says it fits lens up to 84mm.
Title: Mamiya 28mm Lens filter question
Post by: ternst on March 05, 2008, 11:26:52 pm
Don, I guess I must have put a 1 in front of that lens cap price - I thought for sure it was over $100 at B&H. That is not a bad price at all. I'm shooting a lot of waterfalls right now and would sure miss a polarizer if I could not use one.
Title: Mamiya 28mm Lens filter question
Post by: Don Libby on March 05, 2008, 11:54:33 pm
Quote
Don, I guess I must have put a 1 in front of that lens cap price - I thought for sure it was over $100 at B&H. That is not a bad price at all. I'm shooting a lot of waterfalls right now and would sure miss a polarizer if I could not use one.
[a href=\"index.php?act=findpost&pid=179475\"][{POST_SNAPBACK}][/a]


Just double checked the B&H price - it is $31.00 and they are accepting orders.  I also had a thought about a mailing tube but they are either a tad too small or too big.  You'd need a 3.5" opening to fit.  The lens cap is looking better and better..

don
Title: Mamiya 28mm Lens filter question
Post by: ternst on March 07, 2008, 07:04:43 pm
A bit of an update on the polarizing filter issue. A 112mm polarizer held tight against the front of the lens hood won't work at all - I just tried it and you can see the entire filter. I'm not sure your lens cap rig will work either...
Title: Mamiya 28mm Lens filter question
Post by: Don Libby on March 14, 2008, 03:50:45 pm
I just recently a couple new Cokin Z-Pro filters (100x150mm) and just yesterday tried them out on the Mamiya 28mm lens.  I shoot the 28 on a P30+ so I also have the Mamiya crop screen in my viewfinder.  I found that I could hold the filter up to the sunshade and if I was very careful have the filter cover the image.  The 100x150mm filters just come to the very sides of the crop lines so there's not a lot of room for errors (which showed up on a couple images).  All in all, I say that if you are using a 28 with a P30 then using the crop screen you should have little problems.

I've also decided to pick up a spare lens cap in order to retrofit to see if I can come up with a more stable way to hold the filters.  Stay tuned as I'll keep those who are interested updated.  This is an important project for me as the trip to Alaska is coming up shortly.

The images contain no post-processing whatsoever they were opened in Bridge then converted to JPEG.  Image 1 shows the filter slipped away while #2 shows it as it should have been.

Sample 1
[attachment=5579:attachment]

Sample 2
[attachment=5580:attachment]


don
Title: Mamiya 28mm Lens filter question
Post by: ternst on March 15, 2008, 07:38:41 am
Looks like you can get away with this with the p-30 but I don't see anything working on the p-45. I would love to hear if anyone does find a solution. I really do miss a polarizer with this lens. Too bad. Thanks!

Tim Ernst in Arkansas
Title: Mamiya 28mm Lens filter question
Post by: j.miller on March 15, 2008, 09:58:13 am
I have found a possible solution, however I have not had a chance to test it. Here goes:

The Cokin X-Pro Filter holder can be affixed to various lenses with traditional screw-in adapter rings. In addition, Cokin has a Universal Ring (# X499) for the X-Pro holder, which uses four (4), nylon-tipped thumbscrews to clamp around the outside diameter of a unusual lens or accessory. This adapter ring will easily accommodate the size and unusual shape of the Mamiya AF 28mm D lens. This adapter ring also allows you to fit the entire filter holder assembly as close to the front element as possible. In fact, will the universal adapter ring, a good portion of the filter holder is behind the front element, as you four (4) thumbscrews are clamped to the rear of the built-in lens hood of the Mamiya 28mm lens.

If I recall, the Cokin X-Pro Glass Circular Polarizing filter is approx 120mm in diameter. This additional diameter over traditional screw-in filters, while being placed as close the front element as possible, might do the trick.

I have used this exact filter holder combination on the Canon and Nikon 14mm f/2.8 lenses, attaching it to the built-in hood with the X-Pro Universal ring, and eliminated vignetting all together. Considering these lenses have a wider angle of view than Mamiya 28mm, there might be some potential here.

As some of you might be aware, the X-Pro system is noticeably better (in regards to construction, design, precision, and filter quality) than the smaller format systems from Cokin. If you can find a dealer who has some Cokin X-Pro stock, take a look!

Once I have a chance to try this out, I will be sure to report back.

Regards,

Jordan Miller

Quote
Looks like you can get away with this with the p-30 but I don't see anything working on the p-45. I would love to hear if anyone does find a solution. I really do miss a polarizer with this lens. Too bad. Thanks!

Tim Ernst in Arkansas
[a href=\"index.php?act=findpost&pid=181664\"][{POST_SNAPBACK}][/a]
Title: Mamiya 28mm Lens filter question
Post by: ternst on March 26, 2008, 07:11:57 pm
The Cokin X-pro system will not work with a p-45 back and the 28mm Mamiya, at least not for a polarizer. The actual glass part of their x164 polarizer is 119mm wide - when placed up flat against the lens hood you can see the full rim of the polarizer in all four corners. I just tried it and it looks terrible. I don't know of any other polarizer that is wider, and even this rig won't really fit well using the universal adapter ring since the screws have to be so long to reach. So it is back to the drawing board. Paul C. told me of a company that will cut off the front of the hood, which would allow the filter to be held closer to the front element, but I have a feeling even that would not be enough - the shallow part of the tulip hood goes back behind the front element, which tells me that even if you had the filter flat up against that bubble element it would not be enough coverage. I guess they had to compromise to make this lens so good, but how could they do without a polarizer is beyond me...

If anyone else finds a solution I would love to hear about it! Thanks...

Tim Ernst in Arkansas
Title: Mamiya 28mm Lens filter question
Post by: Don Libby on March 27, 2008, 12:59:56 am
Here’s my current plan at least for my setup which includes a P30+.

I’ve ordered a lens cover from B&H (still waiting for it to arrive).  I’ve looked at the current cover and placed a Cokin Z 77mm ring up to the rear opening.  The way I figure it is that once the spare lens cover gets here, using a dremmel I’ll cut the solid end off leaving the ring.  I’ll super glue (or something) the 77mm ring adaptor to one end thus allowing me the use of the Z filter holder.  The way I figure it is that by putting the frankenlibby ring on the lens (much the same way you’d put the normal uncut lens cover on) that has the ring adaptor permanently attached to it I should be able to use the Z filter holder and use any of my filters.  If not all I’m out is the cost of the lens cap ($31 US) and my time.


If it works it’ll help those shooting with the P30 and I’ll post images; if it doesn’t I’ll hang my head in shame  

don
Title: Mamiya 28mm Lens filter question
Post by: Henry Goh on March 27, 2008, 03:56:29 am
Wouldn't some Velcro solve this problem?
Title: Mamiya 28mm Lens filter question
Post by: mtomalty on March 27, 2008, 11:18:00 am
Tim


If you haven't already inquired you might want to dig around the Lee filters product.

I recall,from quite a few years ago,that they had a series of square filters (like cokin)
that were considerably larger that the Cokin P series that were designed for the
movie industry.  You might luck into a large square polarizer that could be rigged to
work with your 28mm.

Cokin also had a series of filters,grads for sure but I don't know about pola's that were about
50% larger that their P series


Best,
Mark
Title: Mamiya 28mm Lens filter question
Post by: j.miller on March 27, 2008, 11:44:48 am
Another solution would be to use 138mm round filters intended for Motion Picture / Broadcast applications. This is very common size used in matte boxes by ARRI, Chrosziel, and others. Schneider, Tiffen, and Formatt all make polarizers in this size.

If 138mm is still too small, you could look into the various rectangular filter sizes also available for Motion Picture / Broadcast applications. These include 4"x4", 4"x5.65" (Panavision size), 5"x5", 6.6"x6.6", and several others. Polarizers exist from Schneider, Tiffen, and Formatt in these rectangular sizes as well.

The only problem with all of these filters is they are designed to be used in filter and matte box systems which incorporate all of the necessary mechanics to hold and manipulate the filters in front of the lens. Outside of a matte box, there is not an easy way to hold the filters in place, without developing a custom filter holder.

I have seen several companies, who cater to the motion picture industry who develop custom lens adapters, filter holders, and other random gadgetry.

Paul Duclos of Duclos Lenses is well respected in the motion picture community. see www.ducloslenses.com (http://www.ducloslenses.com).

Lentequip is also well known for various lens / filter / matte box related accessories. see www.lentequip.com (http://www.lentequip.com).

I will have to refer to some notes to find more contacts in the motion picture industry for this type of application.

You might be able to use components from ARRI or Chrosziel light-weight matte box or sunshade, to accomplish this as well.

Regards,

Jordan Miller
Title: Mamiya 28mm Lens filter question
Post by: ternst on March 27, 2008, 05:47:24 pm
OK, thanks for the info. Anything would have to be AT LEAST 5" across - the Cokin P filters are quite tiny in comparison - their x-pro series that I tried were 119mm (about 5") and the polarizer was not wide enough - their resin filters were fine at 5" x 6" but anything smaller would not cut it, and a round one would need to be at least 130mm and perhaps larger.

One other item I discovered is that with so much of the glass filter sticking out beyond the width of the lens barrel, you get reflections from behind that bounce off of the rear of the filter and right onto the sensor - so even if any of these movie filters were large enough to cover the spread you would have to come up with something to keep them from reflecting from the rear - getting to be quite a serious contraption for sure!

I was able to mount the x-pro with universal adapter to the lens hood and it worked just fine with their 5" x 6" resin filters - if they had a polarizer that size (or 5" x 5") that would work fine, but the only polarizers that Cokin makes are round. I don't know if Lee or anyone else makes 5" square polarizers...
Title: Mamiya 28mm Lens filter question
Post by: ternst on March 27, 2008, 05:49:59 pm
-Cokin also had a series of filters,grads for sure but I don't know about pola's that were about
50% larger that their P series-

Mark:

Yup, the x- series and the z-series. The x-pro are the ones I'm trying - they are the largest - and the polarizer is still too small (see above). Their polarizers are all round. I can smell a solution, but it is getting pretty expensive....
Title: Mamiya 28mm Lens filter question
Post by: Paul2660 on March 28, 2008, 12:07:36 am
Cokin makes a linear polarizer, I believe it's 5 x 5 for the Z pro.  It's not 5 x6 since there is no grad required.  Linear would be full on all the time, which should work fine.

You will lose the CL effect, rotating to full effect to less effect. But it should cut the glare.

Paul C
Title: Mamiya 28mm Lens filter question
Post by: ternst on March 28, 2008, 07:26:47 am
Paul:

I could not find anything Cokin but round polarizers. Do you have a part number? Their x-pro takes 5" filters - the z-pro is much smaller and takes 4" filters (I would have through the "z" to be larger!). Nothing on their web page. I ordered a Schneider 6.6" square polarizer from Hollywood and will give that a shot - I'll have to tape it to the front of the Cokin folder but for now that will be fine. The only Lee filters I found were 4" x 4", but Jordan was correct - there are lots of large filters in the movie industry, including 5.6" & 6.6" square ones and 128mm and 136mm round ones, although the round ones many not be large enough to cover the corners, which is why I went with the large square one.

I found a couple of things interesting - first, that my beloved B&H was priced WAY HIGH for the Cokin filter system I ordered the other day (vs. Adorama - the same polarizing filter, holder, universal adapter, and one gel filter came to about $250 less than B&H - Adorama had ALL of the descriptions listed wrong on their web site, but the part numbers were correct, and they shipped the correct stuff). And that the big Hollywood filters from Schneider and Tiffen were cheaper than the big Cokins - the 119mm x-pro Cokin polarizer was over $400 while the 6.6" Schneider was less than $400.

And one other question for those of you in the know - all of these "Hollywood" filters advertise as being cut from "water white" glass, and that they are much more effective than standard polarizing filters, up to "12" times as much. Anyone know that they are talking about? Obviously a bunch of marketing hype, but is there anything to this vs. the standard B&W or other high quality polarizing filters we mere still mortal still photographers use?

--- The Schneider 6.6x6.6" Circular True-Polarizing Glass filter is by far the most effective polarizer for motion picture and television cameras. Having an extinction ratio of ER 374, the Schneider True-Pol is 12 times more effective than other polarizing filters, and is unmatched in its ability.

The polarizing film in a Schneider True-Pol filter is laminated between two pieces of Schneider's crystal-clear, water-white optical glass. ---
Title: Mamiya 28mm Lens filter question
Post by: Paul2660 on March 28, 2008, 11:38:49 am
Tim,

You are correct it appears that the Cokin Linear is still round.  Adorama's site displays it as square.  

Paul
Title: Mamiya 28mm Lens filter question
Post by: ternst on March 31, 2008, 09:40:04 pm
Monday update on this silly polarizing filter issue. I received a Schneider 5.6" x 5.6" polarizing filter today (about $400) and can happily report that it DOES cover the entire 28mm view on a p-45 back. I taped it to the front of a Cokin x-pro filter holder (130mm across) and attached that to the 28mm lens via the Cokin universal adapter. This is not a very good solution and in fact takes several minutes to set up, but it does work, and you can rotate the front of the filter holder with the filter attached so you have full control and there is no vignetting. If I can find a spare lens cap for this lens I will trim it back and attach the universal adapter to it permanently, and that would allow me to slide the entire rig over the front of the lens and make it all much quicker and more effective.

Anyone find a source for the 28mm lens cap?

I know many of you who own this lens continue to laugh at my efforts to find a polarizing filter as you don't see the need, but it seems like every time I use this lens I really need a polarizing filter, so now, at last, I will be able to use this lens to its full potential. I love the rich, saturated colors I can get out in the deep woods with a polarizer, especially on wet, overcast days (lots of great waterfalls in my neck of the woods right now)...

Thanks to all who offered thoughts on this issue!

Tim Ernst in Arkansas
Title: Mamiya 28mm Lens filter question
Post by: Don Libby on March 31, 2008, 09:59:58 pm
Tim

Great news and thank you for the update.  I placed an order with B&H about a week ago for a spare lens holder - I'm still waiting.  Where did you get the universal adapter from?  Care to post a image of the result as given in your update?

And the great search continues....


don
Title: Mamiya 28mm Lens filter question
Post by: ternst on March 31, 2008, 10:25:25 pm
I got the universal adapter from Adorama but B&H has them too, just more expensive. I will try to take some snaps of the setup in the next day and post here. I think with that lens cap acting as an inside rim for this universal adapter the rig will work pretty well, but it will take up a good bit of space in the camera pack.

The universal adapter is normally attached to the lens hood via four long pointed screws, and you only have about 1/2" or less of lens hood to work with, plus you don't actually want to tighten the screws directly onto the hood since you would scratch it. My thinking was to cut off the rear 3/4" or so of the lens cap and attach those four screws directly to it and taping over any open areas behind the polarizing filter so reflections won't be an issue, then the lens cap should slide onto the lens hood and fit snugly, allowing you to rotate the filter holder (taping the heavy glass filter to the front of the filter holder). A photo will be much better, but since I don't have an extra lens cap it will look pretty bad so please don't laugh too much when I get around to shooting and posting...

tim ernst in arkansas
Title: Mamiya 28mm Lens filter question
Post by: Don Libby on March 31, 2008, 10:48:43 pm
Quote
. A photo will be much better, but since I don't have an extra lens cap it will look pretty bad so please don't laugh too much when I get around to shooting and posting...

Tim

While I might snicker I promise I won’t laugh!  This is an important project for me as well as I want to have this done before I head for Alaska in a couple months.

don

Edit:  What is the part # for the adapter?
Title: Mamiya 28mm Lens filter question
Post by: ternst on April 01, 2008, 07:19:13 am
Don:

Here is the adapter that I got, which is for the x-pro system, their largest filter holder (the z-pro is a 4" system) - x-499

At B&H (http://www.bhphotovideo.com/c/product/168533-REG/Cokin_CX499_X_Pro_Universal_Adapter_Ring.html)

at Adorama (http://www.adorama.com/CKUVXP.html?searchinfo=cokin%20universal&item_no=2)

Paul Caldwell is working on getting a special filter cut down to fit the Cokin x-pro holder, although I don't know if the glass is thin enough to fit - the big "hollywood" glass filters are very thick.

I'm headed out early this morning to go shoot some waterfalls and will be able to test the new filter to see how it works...
Title: Mamiya 28mm Lens filter question
Post by: Don Libby on April 01, 2008, 01:08:45 pm
Quote
Here is the adapter that I got, which is for the x-pro system, their largest filter holder (the z-pro is a 4" system) - x-499

Will this work on the Z as well or is there another, the only reference I can find is for the smaller P system.

Thanks

don
Title: Mamiya 28mm Lens filter question
Post by: ternst on April 01, 2008, 01:20:14 pm
Since the z system is so much smaller I doubt it - the outside rim of this universal adapter is very large to fit the x-pro. I thought I saw a reference to a universal adapter for the z system? I bet they have one, but those filters are only 4" so I didn't pay much attention. I found the Cokin web page useful and had all of their systems and individual items listed...
Title: Mamiya 28mm Lens filter question
Post by: Paul2660 on April 01, 2008, 01:22:41 pm
Don,

You want the X-pro system.  The z is smaller.  
Cokin sells the adapter separately and then you will need universal adapter ring to mount the holder to the lens shade.


Link to the X-Pro holder:
http://www.bhphotovideo.com/c/product/1692...er_Requires.htm (http://www.bhphotovideo.com/c/product/169219-REG/Cokin_CBX100_X_Pro_Filter_Holder_Requires.htm)

Link to the universal adapter:
http://www.bhphotovideo.com/bnh/controller...earch&Q=*&bhs=t (http://www.bhphotovideo.com/bnh/controller/home?shs=X-Pro+Universal+Adapter+Ring&ci=0&sb=ps&pn=1&sq=desc&InitialSearch=yes&O=productlist.jsp&A=search&Q=*&bhs=t)

This should get you started.  I have not heard anything back from tiffen on cutting down their 5.65 x 5.65 linear filter.  Checked on it again today, no response.

Paul l
Title: Mamiya 28mm Lens filter question
Post by: Paul2660 on April 01, 2008, 01:34:29 pm
Lens Cap for the 28mm is part number 210-635.
Mamiya USA currently has them in stock, $47.00

914-347-3300


PFC
Title: Mamiya 28mm Lens filter question
Post by: ternst on April 01, 2008, 03:13:35 pm
Hey THANKS for that info Paul! Keep us posted on the tiffen glass.
Title: Mamiya 28mm Lens filter question
Post by: Don Libby on April 11, 2008, 08:00:50 pm
I ordered an extra front lens cap from B&H on March 13th and it was delivered today.  This is not one of their normally stocked items and it took them awhile to get it and ship it out.  The price of the cap was $31.00 total cost including shipping came to $37.85.  This now qualifies as the less expensive accessory I’ve brought for MF.

My thought process was to cut the very leading edge from the cap then using the Cokin X-Pro universal adapter mount the X-Pro filter holder to it.  

I spent about 30 minutes cutting the front off.  This is the first time I every brought something to deliberately cut into and possible ruin it.  Taking my time I was able to get a pretty clean cut (still need to clean it up some).  

This is what I’ve found so far.  

•The adapter works and fit okay on the cut cover.
•The filter holder works well on the adapter.  Keeping the two brass screws loose allows the filter holder to move freely.
•The circular filter fits into the filter holder and works as intended.
•The concept WORKS!

It may not look good but it sure as hell works.  I plan on cleaning up some of the cutting marks and I think I might make 4 small intents/holes so that the screws fit a bit better.  

Hope the following images help clear up any confusion from this write-up.

don

[attachment=6065:attachment]
[attachment=6064:attachment]
[attachment=6063:attachment]  [attachment=6062:attachment]
[attachment=6060:attachment]  [attachment=6061:attachment]

Yes, I know the filter is dusty!
Title: Mamiya 28mm Lens filter question
Post by: mcfoto on April 11, 2008, 10:03:11 pm
Quote
I ordered an extra front lens cap from B&H on March 13th and it was delivered today.  This is not one of their normally stocked items and it took them awhile to get it and ship it out.  The price of the cap was $31.00 total cost including shipping came to $37.85.  This now qualifies as the less expensive accessory I’ve brought for MF.

My thought process was to cut the very leading edge from the cap then using the Cokin X-Pro universal adapter mount the X-Pro filter holder to it. 

I spent about 30 minutes cutting the front off.  This is the first time I every brought something to deliberately cut into and possible ruin it.  Taking my time I was able to get a pretty clean cut (still need to clean it up some). 

This is what I’ve found so far.   

•The adapter works and fit okay on the cut cover.
•The filter holder works well on the adapter.  Keeping the two brass screws loose allows the filter holder to move freely.
•The circular filter fits into the filter holder and works as intended.
•The concept WORKS!

It may not look good but it sure as hell works.  I plan on cleaning up some of the cutting marks and I think I might make 4 small intents/holes so that the screws fit a bit better. 

Hope the following images help clear up any confusion from this write-up.

don

[attachment=6065:attachment]
[attachment=6064:attachment]
[attachment=6063:attachment]  [attachment=6062:attachment]
[attachment=6060:attachment]  [attachment=6061:attachment]

Yes, I know the filter is dusty!
[a href=\"index.php?act=findpost&pid=188842\"][{POST_SNAPBACK}][/a]

Hi
Well done. If you took this to a jeweler they could do a nice clean cut. Should send what you have done to Really Right Stuff & see what they could make, providing there is enough demand.
Thanks Denis
Title: Mamiya 28mm Lens filter question
Post by: Don Libby on April 11, 2008, 10:28:41 pm
Thanks Denis

Wanted to add this image as well.

[attachment=6066:attachment]

don
Title: Mamiya 28mm Lens filter question
Post by: Paul2660 on April 12, 2008, 10:18:03 am
Don, thanks for the images.  BTW, what did you use to cut the extra lens cap.  You picks showed what I was afraid of, the plastic will shatter when you try to cut it.

Also with it on that way, do you get good tension on the lens shade, such that if you have the camera pointed down, the rig won't slide off?

I never heard back from Tiffen, they don't seem interested.  The glass size needs to be 3mm thick to fit inside the X-Pro holder.  The schneider 5.65 x 5.65 is about 4mm thick but also too wide.  I also realized if I had mine cut I would have sharp edges and it would just make for more work.  

Paul C
Title: Mamiya 28mm Lens filter question
Post by: Don Libby on April 12, 2008, 11:06:30 am
I used a dremel and a plastic cutting wheel to cut the lens cap.  The plastic did not shatter, what you see is plastic shavings made from the cut.  I took my time cutting the very edge of the cap off but even with that I still have the shavings, afterwards I smoothed the shavings down.  It may not look pretty but it works.

I put the cap back on the same way it would be if the front were one it, that way the inner bevel is holding on to the lens and remains nice and tight.  I don’t think there’d be a problem with the lens pointed down with the frankenlibby design on as it is a tight fit.  I’ve played with the filter holder and circular filter on the lens and can move each freely without disturbing the setup.  The screws are leaving a mark in the plastic and I think I might just drill a hole so that I can fit the adapter back in the same place each time.  

I still think that I might attempt to permanently mount a ring to the end of the plastic thus eliminating the need of the adapter – might attempt that later today.

All in all this winds up being relatively sturdy with the adapter and filter holder in place, just a bit awkward with the four large screws protruding that’s why I want to try just a normal ring and filter holder….stay tuned.

BTW – no sharp edges after the cut.

Also as my wife just reminded me – cut outside as the smell of heated plastic is not all that pleasant!

don
Title: Mamiya 28mm Lens filter question
Post by: Don Libby on April 12, 2008, 12:24:37 pm
Not so good news to report.

Attempted to superglue a ring to the cap without success, just wouldn’t stick to each other.

Vignetting….

When I looked through the lens yesterday afternoon I had the filter in place thus I failed to see any vignetting.  I had the camera outside this morning and looked thru the lens with just the lens cap/filter holder on – the lens cap produces vignetting.  While most of the vignetting is outside of the P30’s crop lines there still some that goes into the image area thus making this solution for P30 only and not for P45’s.

I’ve included four images.

View without device                    View with device only
[attachment=6071:attachment]                  [attachment=6072:attachment]
View with circular filter                    Cropped image
[attachment=6073:attachment]                  [attachment=6074:attachment]

While I think I can use this in a very limited way I’m now retiring from this endeavor and more than willing to let others pick it up from here.  

don
Title: Mamiya 28mm Lens filter question
Post by: Paul2660 on April 12, 2008, 04:12:33 pm
the lens cap must be vignetting where the tulip dips are.  

However can you test one thing?  Tim reported that the Cokin CL-PL did the same thing as your image showed, the hard vignetting around the corners.  Can you try the lens cap mount and Universal adapter without the CL-PL and see if you still see the vignetting?

Thanks
Paul C
Title: Mamiya 28mm Lens filter question
Post by: Don Libby on April 12, 2008, 05:10:31 pm
Quote
the lens cap must be vignetting where the tulip dips are. 

However can you test one thing?  Tim reported that the Cokin CL-PL did the same thing as your image showed, the hard vignetting around the corners.  Can you try the lens cap mount and Universal adapter without the CL-PL and see if you still see the vignetting?

Thanks
Paul C
[a href=\"index.php?act=findpost&pid=189025\"][{POST_SNAPBACK}][/a]

You're correct, it's being caused by the lens cap.  Image #2, shows the vignetting occuring with the lens cap, universal adapter and filter holder on.  Image #3 includes the CL-CP.  Image #4 shows the usable crop.

I'll be at the Gila Cliff Dwellings next week and will try this gizmo out there.  I know I'll have vignetting but I want to see what the usable image might be.  

don
Title: Mamiya 28mm Lens filter question
Post by: HarperPhotos on April 12, 2008, 05:29:07 pm
Gidday,

Got the New Zealand rep Tim to ask Mamiya Japan if they were going to make a filter attachment for the Mamiya 28mm and the reply was NO.

Cheers

Simon
Title: Mamiya 28mm Lens filter question
Post by: ternst on April 13, 2008, 04:48:43 pm
The polarizing filter rig that I made up for my 28mm with P-45+ works fine with no vignetting. I used the Cokin x-pro holder with universal adapter. I removed the four screws from the adapter, and then cut out a foam ring that fit snugly over the lens hood. The outside of this foam ring fit snugly inside the universal adapter ring, and then I taped them together - this way I did not need to use those screws at all.

I put four small bits of velcro on the outside end of the filter holder, and matching velcro strips on the inside side of the Schneider 5.6" x 5.6" polarizer. When I need to use the filter I simply slip the Cokin holder over the lens (I also added some tape on the lens hood to act as a stop for the filter holder), then stick the heavy piece of glass onto the front of the filter via the velcro. The rig will rotate just fine and there is no vignetting. There are some reflections from the top corners of the filter, but I simply lay the filter case on top of the lens to cover it up and it is fine. I've been shooting a bunch of waterfalls in Arkansas this week and have used this setup a dozen times or so with no issues.

Tim Ernst in Arkansas
Title: Mamiya 28mm Lens filter question
Post by: Don Libby on April 13, 2008, 06:24:34 pm
Quote
The polarizing filter rig that I made up for my 28mm with P-45+ works fine with no vignetting. I used the Cokin x-pro holder with universal adapter. I removed the four screws from the adapter, and then cut out a foam ring that fit snugly over the lens hood. The outside of this foam ring fit snugly inside the universal adapter ring, and then I taped them together - this way I did not need to use those screws at all.

I put four small bits of velcro on the outside end of the filter holder, and matching velcro strips on the inside side of the Schneider 5.6" x 5.6" polarizer. When I need to use the filter I simply slip the Cokin holder over the lens (I also added some tape on the lens hood to act as a stop for the filter holder), then stick the heavy piece of glass onto the front of the filter via the velcro. The rig will rotate just fine and there is no vignetting. There are some reflections from the top corners of the filter, but I simply lay the filter case on top of the lens to cover it up and it is fine. I've been shooting a bunch of waterfalls in Arkansas this week and have used this setup a dozen times or so with no issues.

Tim Ernst in Arkansas
[a href=\"index.php?act=findpost&pid=189281\"][{POST_SNAPBACK}][/a]

Tim

I showed you mine how 'bout a couple images of yours?

don
Title: Mamiya 28mm Lens filter question
Post by: Paul2660 on April 14, 2008, 12:12:20 pm
The foam works, like Tim pointed out.  This keeps most of the reflected light from coming back in around the opening where the screws are.  I used mini-cell, gray, most common in whitewater kayak walls.  I cut out a ring of the foam based on the diameter of the Universal adapter, then made an inner cut out for the lens shade.  This works, fine the mini cell has a good grip and holds the X-Pro on well.   Then mounting the Glass sheet from Schneider is the final step.  I have yet to find a really quick way to get the mounting of the glass, but Velcro sounds like a good idea.   You will still need to cover the top of the rig as the glass sheet pulls in reflections from the top, I used a dark cotton cloth for that.   Over time Mini cell will harden so it will need to be replaced over time.

Tim, did you use the Velcro self adhesive style?  It gets a good enough grip I guess.  

I also found out that most of the time, when I had the rig 100% polarized, the sheet wasn't lined up square, most times it was lined up at an angle from 90 degrees.  

In shooting over the weekend, I never had a great feeling that the sheet wasn't going to fall off the way I was securing it, so I need to move to the Velcro.

Paul C
Title: Mamiya 28mm Lens filter question
Post by: ternst on April 14, 2008, 01:09:24 pm
Here are a couple shots from my setup. The self-stick velcro works great on the holder but I've already had a couple come off from the glass so I keep a some already cutup in my pocket. I pointed it down over a 110' cliff the other day and just held my breath...
Title: Mamiya 28mm Lens filter question
Post by: Paul2660 on April 14, 2008, 01:14:46 pm
Tim,  

I had been using rubber bands to hold the glass in place.  The ones that come on broccoli, short blue or red ones that are a tad wider than normal rubber bands.  This combined with Velcro would be a good safe guard to the sheet falling off.

Paul
Title: Mamiya 28mm Lens filter question
Post by: Don Libby on April 14, 2008, 02:52:49 pm
Tim

Thanks for posting the images; you did a much better job of it than I did.  I like the idea of using a foam ring instead of the lens cap however it appears that the way it mounts (further back) eliminates the use of a CL-PL.  Can you move the ring closer to the leading edge in order to mount the CL-PL and not get vignetting?

I’m headed to the Gila Cliff Dwellings to test my contraception out; this will be the last chance to test prior to the Alaska trip in May then it’ll be too late.

don



Quote
Here are a couple shots from my setup. The self-stick velcro works great on the holder but I've already had a couple come off from the glass so I keep a some already cutup in my pocket. I pointed it down over a 110' cliff the other day and just held my breath...
[a href=\"index.php?act=findpost&pid=189445\"][{POST_SNAPBACK}][/a]
Title: Mamiya 28mm Lens filter question
Post by: ternst on April 14, 2008, 02:56:22 pm
What is the CL-PL? If that is the round polarizer, then yes, you can mount it either direction, you would just need to position the holder however you need to and make sure it is snug - mine is set up so that it goes all the way back, but I also use a sunset filter in one of the slots and just don't push the holder back as far and it works fine. You cannot use the round polarizer with the p-45 back, but you have the p-30, right? I don't know how it would work with that one.