Pages: 1 ... 7 8 [9] 10 11 ... 16   Go Down

Author Topic: DIGITAL Medium Format photography is almost as moribund???  (Read 118367 times)

jerome_m

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 670
Re: DIGITAL Medium Format photography is almost as moribund???
« Reply #160 on: March 06, 2013, 07:33:55 am »

Hi Jerome,

Working on it, will send you a PM with login info this evening.

Best regards
Erik

I will send you the files, but I can already predict what you will find out: namely, that the two cameras show the same detail at the pixel level. Quite simply because your tests are designed in that way. By reducing all variables to the most limited set for which the D800 can equal a MF camera and refusing to consider MF cameras with higher resolution, you will necessary find out that the D800 gives equal results.

What I am trying to demonstrate here is that the problem in this discussion is not the cameras. The problem is the test. It is not a fair test. I post a couple of images which do not favour the D800, and immediately you argue that I should have used MLU and a Zeiss lens.  You did not argue once that I should have used a better Hasselblad or a different MF lens. You did not even answer when I suggested, twice, that a better MF should be used. You are biased.

Interestingly, the reason why the D800 looked less sharp is because Nikon chose to process the jpeg in that way. That alone should prove to all of us how flawed that particular test is, but nobody noticed.

I'll say it again: the real advantages of a MF camera over a D800 have nothing to do with how sharp each camera is at the pixel level. Now, find out what they really are.
Logged

ErikKaffehr

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 11311
    • Echophoto
Re: DIGITAL Medium Format photography is almost as moribund???
« Reply #161 on: March 06, 2013, 02:23:26 pm »

Hi,

I don't know what I would find.

Regarding high resolution MF I have published an article, comparing IQ-180 with a very good lens and the Nikon D800E also with a very good lens here (IQ 180 to the left Nikon to the right:





In the upper image I upsized the Nikon image to IQ180 image size and in the lower one the IQ180 image was downsized to Nikon size and still kept a significant advantage.

http://echophoto.dnsalias.net/ekr/index.php/photoarticles/71-mf-digital-myths-or-facts?start=5

In general I'm pretty sure that a larger sensor has advantages in two areas:

Higher MTF on fine detail.

Smoother midtones.

Smaller formats may compensate with better lenses and larger apertures. I am not sure this is the case, especially after I have tested an old Sonnar 150/4 comparing to an old Minolta 80-200/2.8 APO and a Sony 70-400/4-5.6G on a Sony Alpha 77. The data here are based an APS-C sensor. Little doubt that this lens would give superior performance on a much larger sensor.

http://echophoto.dnsalias.net/ekr/index.php/photoarticles/73-sonnar-150-cb-on-dslr-using-arax-tilt-adapter



Best regards
Erik




I will send you the files, but I can already predict what you will find out: namely, that the two cameras show the same detail at the pixel level. Quite simply because your tests are designed in that way. By reducing all variables to the most limited set for which the D800 can equal a MF camera and refusing to consider MF cameras with higher resolution, you will necessary find out that the D800 gives equal results.

What I am trying to demonstrate here is that the problem in this discussion is not the cameras. The problem is the test. It is not a fair test. I post a couple of images which do not favour the D800, and immediately you argue that I should have used MLU and a Zeiss lens.  You did not argue once that I should have used a better Hasselblad or a different MF lens. You did not even answer when I suggested, twice, that a better MF should be used. You are biased.

Interestingly, the reason why the D800 looked less sharp is because Nikon chose to process the jpeg in that way. That alone should prove to all of us how flawed that particular test is, but nobody noticed.

I'll say it again: the real advantages of a MF camera over a D800 have nothing to do with how sharp each camera is at the pixel level. Now, find out what they really are.
« Last Edit: March 06, 2013, 03:21:54 pm by ErikKaffehr »
Logged
Erik Kaffehr
 

ErikKaffehr

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 11311
    • Echophoto
Re: DIGITAL Medium Format photography is almost as moribund???
« Reply #162 on: March 06, 2013, 04:10:59 pm »

Hi,

I got two RAW files from "Jerome_m", thanks a lot!

Here is what I did:

Loaded both into Lightroom 4.3

Match exposure
Adjusted exposure to be similar on tablecloth at center
Adjusted white balance on table cloth at center
Activated removal of later chromatic aberration on both
Used similar sharpening on both (Amount 100 (104 on Nikon) and radius 1 all others at zero.

I'll recheck settings and images tomorrow, this is a first look.

Hasselblad left Nikon right.

If we had a higher resolution Hasselblad, then I would upsize the Nikon image to that size. But these images are same width (short dimension).

Sharpening setting always to taste, but the ones I use were quite OK in my eyes.

My findings? Somewhat more fine detail contrast on the Hasselblad. Corners on the Hasselblad sharper.

 

Best regards
Erik

Three crops, two central and one corner. All at actual pixels. The images have similar short side so I did resample neither. This corresponds to both images printed same size.
« Last Edit: March 06, 2013, 04:13:42 pm by ErikKaffehr »
Logged
Erik Kaffehr
 

FredBGG

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 1630
Re: DIGITAL Medium Format photography is almost as moribund???
« Reply #163 on: March 06, 2013, 09:18:34 pm »

Hi,

I got two RAW files from "Jerome_m", thanks a lot!

Here is what I did:

Loaded both into Lightroom 4.3

Match exposure
Adjusted exposure to be similar on tablecloth at center
Adjusted white balance on table cloth at center
Activated removal of later chromatic aberration on both
Used similar sharpening on both (Amount 100 (104 on Nikon) and radius 1 all others at zero.

I'll recheck settings and images tomorrow, this is a first look.

Hasselblad left Nikon right.

If we had a higher resolution Hasselblad, then I would upsize the Nikon image to that size. But these images are same width (short dimension).

Sharpening setting always to taste, but the ones I use were quite OK in my eyes.

My findings? Somewhat more fine detail contrast on the Hasselblad. Corners on the Hasselblad sharper.

 

Best regards
Erik

Three crops, two central and one corner. All at actual pixels. The images have similar short side so I did resample neither. This corresponds to both images printed same size.


You should scale down the Nikon so that the subject matter is the same size on screen for the side by side images.

Here are your crops with the Nikon scales to match the Hasselblad



Here they are side by side.



or here http://farm9.staticflickr.com/8523/8534907099_f19fd1344c_o.jpg
« Last Edit: March 06, 2013, 10:04:58 pm by FredBGG »
Logged

ErikKaffehr

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 11311
    • Echophoto
Re: DIGITAL Medium Format photography is almost as moribund???
« Reply #164 on: March 06, 2013, 11:50:41 pm »

Hi Fred,

I don't think so. I would normally scales the images so short size of the image would match, but in this case the image size are so close that I don't think it really matters, Nikon is 4912 and Hassy is 4872. Resizing affects image quality, BTW.

This is not a scientific test, like shooting res charts in lab conditions and evaluating MTF. In a scientific test distance and zooming would be adjusted so FOV would match. This is a real world comparison.

I would expect Hasselblad to have a small advantage, as the pixels are larger. Also the Nikon is OLP filtered and that would demand more sharpening than the blad, so optimal processing would be different. Here I choose a reasonable sharpening for the Nikon and the same sharpening also seems to be OK on the Hasselblad.

As Jerome pointed out, Hasselblad backs are available with higher resolution and that is not the case with Nikon.

Would I make one m wide prints (short side one meter) I'm pretty sure I couldn't tell prints apart if not looking for known problems. Like color moiré on some subjects or not very sharp corners on the Nikon image.

Jerome is also right that the seven year old Hasselblad still delivers very good image quality. A seven year old Nikon DSLR would not even come close. A very high end back will give much better sharpness, and I'm pretty sure there are limits on how far DSLRs can improve. I am sure that 50-60 MP are possible with DSLR but precision, lenses and alignment issues seem to be common with the Nikon D800, at least for really critical users.

Best regards
Erik





You should scale down the Nikon so that the subject matter is the same size on screen for the side by side images.


« Last Edit: March 07, 2013, 01:32:42 am by ErikKaffehr »
Logged
Erik Kaffehr
 

jerome_m

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 670
Re: DIGITAL Medium Format photography is almost as moribund???
« Reply #165 on: March 07, 2013, 03:28:53 am »

As I predicted, you found out that the two cameras give very similar results at the pixel level. This is no surprise: if you design the test so that:
-the subject has the same size per pixel
-the optics are used in a way to minimise aberrations
-processing is the same
-colours are matched and
-there is enough light and not too much dynamic range,
you will find out that all cameras give similar results at the pixel level. The simple reason is that the only difference would be the presence or absence of an anti-moiré low pass filter. The test is designed to make all other factors equal.

But what you don't see from the pictures is more important:
-the H3D has much better and much more accurate AF, I must use live view on the D800 to come close (this was a real surprise of mine)
-the Hasselblad lenses are much better and perfectly usable wide open. Nikon does not have a prime coming close to the Hasselblad 28mm (which has about a 21mm equivalent FOV on the H3D-31). The 12-24 is Nikon's best wide angle lens. The only alternative would be the Zeiss 21mm and the Hasselblad lens is still better and has AF. Lenses always have been small format's Achille's heel
-the H3D has much, much better colours out of the box, especially skin colours. Sure, I can spend an hour to tweak the Nikon's output to look better, but for a pro in fashion, the capability to output perfect skin colours without effort is invaluable.
-the H3D is much easier to shoot tethered, which is again invaluable for many pros (most of them shoot catalogues pictures)
-medium format will make limited depth of field look nicer, which is essential for portraits. The reasons here are complex, I may come back to that later
-and of course recent MF cameras have much higher resolution.

Sure, the D800 has other advantages. I am not listing them here not because I want to minimise them, but because we all know about them. The point is that your "test" does not show all the practical advantages that count to people who buy MF cameras, because of the way it is designed.
Logged

Rob C

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 24074
Re: DIGITAL Medium Format photography is almost as moribund???
« Reply #166 on: March 07, 2013, 05:28:56 am »

Lenses always have been small format's Achille's heel



That's not my experience at all.

Having has Nikon F, F2 Photomic, F3 and F4s with an arsenal of primes from 24mm to 500mm and run two 500 Series Hasselblads beside them; having had Rollei TLR, Mamiya TLR, Bronica 6x7 and Pentax 67 ll, all with a range of primes. I would say that the opposite conclusion to yours is my view on the matter.

I've never owned but have printed from M3 with 21mm and that was out of this world. Leica is still regarded as maker of perhaps the world's best lenses and that reputation was built on 135 format.

The lure of going to 6x7 was always the imagined idea that one was going to spread the same optical quality over four times (+ or -) the area of the film: doesn't work like that. All you get is a different 'look' to your prints or transparencies because of smaller enlargement at same-size prints, and I've actually run tests using a 24mm x 36mm section of a 'blad negative and compared the same thing from a Nkon negative covering exactly the same subject area. The result: a cropped section of a 120 film neg compared with a full 135 neg does not offer the same quality: the full 135 format is better than the cropped 120 format. (I'm talking about using the same film in each format, of course.) Apparently, optical engineering does not allow for the simplistic idea of just scaling up and maintaining the same level of highest quality across formats.

Rob C

jerome_m

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 670
Re: DIGITAL Medium Format photography is almost as moribund???
« Reply #167 on: March 07, 2013, 07:10:28 am »



That's not my experience at all.

Having has Nikon F, F2 Photomic, F3 and F4s with an arsenal of primes from 24mm to 500mm and run two 500 Series Hasselblads beside them; having had Rollei TLR, Mamiya TLR, Bronica 6x7 and Pentax 67 ll, all with a range of primes. I would say that the opposite conclusion to yours is my view on the matter.

I've never owned but have printed from M3 with 21mm and that was out of this world. Leica is still regarded as maker of perhaps the world's best lenses and that reputation was built on 135 format.

The lure of going to 6x7 was always the imagined idea that one was going to spread the same optical quality over four times (+ or -) the area of the film: doesn't work like that. All you get is a different 'look' to your prints or transparencies because of smaller enlargement at same-size prints, and I've actually run tests using a 24mm x 36mm section of a 'blad negative and compared the same thing from a Nkon negative covering exactly the same subject area. The result: a cropped section of a 120 film neg compared with a full 135 neg does not offer the same quality: the full 135 format is better than the cropped 120 format. (I'm talking about using the same film in each format, of course.) Apparently, optical engineering does not allow for the simplistic idea of just scaling up and maintaining the same level of highest quality across formats.

You are right, small format lenses can achieve a higher resolution on their format and MF lenses usually do not spread the same optical quality over a larger area (certainly for the ones designed for film). But this is not at all what I had in mind. What I meant is that, in current photographic practice, large format lenses can use a relatively primitive optical formula and that does not cause noticeable optical defects and photographers always experienced problems with small format lenses (unless -maybe- when the optical designer pulled all his tricks) and MF sat somewhere in between.

Part of the reason is that we do not need the same enlargements, as you rightfully noted. Another part is that we do not use the same apertures. A third reason is, in the case of MF, that the optical engineer allows the lenses to become quite large.
Logged

theguywitha645d

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 970
Re: DIGITAL Medium Format photography is almost as moribund???
« Reply #168 on: March 07, 2013, 11:05:16 am »

Resolving power or contrast, take your pick. You cannot optimize a lens design for both at the same time. As the format gets smaller, you need to go toward resolving power and sacrifice contrast. That is why small format lenses, while having great resolving power, look flat.

But the "it is made for a larger format and so it will be worse than a smaller format lens" hypothesis can be taken so far. There are some great medium-format film lenses that are great on formats smaller than they were designed for.
Logged

TMARK

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 1841
Re: DIGITAL Medium Format photography is almost as moribund???
« Reply #169 on: March 07, 2013, 12:05:26 pm »

Resolving power or contrast, take your pick. You cannot optimize a lens design for both at the same time. As the format gets smaller, you need to go toward resolving power and sacrifice contrast. That is why small format lenses, while having great resolving power, look flat.


This is not intended to fan any format war.

I don't know if this is true, mainly because my experience with certain M mount lenses.  The Summicrons I have experience with never appeared flat, in fact are very close to Mamiya 7 images of the same subject matter.  The Zeiss ZM mount 28 2.8 has more contrast than any lens I've ever used.  In any format.  It is also one of the sharpest lenses I've ever used.

I think "flatness" is more a function of shooting conditions (lighting, focal length, F stop, distance to subject), the sensor, and any post work put into a file (or the default curve of film). 
Logged

Rob C

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 24074
Re: DIGITAL Medium Format photography is almost as moribund???
« Reply #170 on: March 07, 2013, 12:31:39 pm »

I think you're right, T; having said which, some M film shooters used to look for older Leitz glass because they tried to achieve a different look to that possible from the modern lenses.

That's partly why so many photographic discussions don't really have anywhere to run: it depends on who is using what and for which ultimate purpose.

Rob C

jerome_m

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 670
Re: DIGITAL Medium Format photography is almost as moribund???
« Reply #171 on: March 07, 2013, 12:48:56 pm »

some M film shooters used to look for older Leitz glass because they tried to achieve a different look to that possible from the modern lenses.

Some older Leitz glass suffered from quite large spherical aberration. While this reduces contrast, it can also give a kind of "glow" to the highlights of a picture, which looks very nice.

In the 19th century, some manufacturers like Pinkham & Smith hand ground portrait lenses for the same reason: increase spherical aberration. This can have desirable effects on depth of field, the rendering of sharp-unsharp transitions, the rendering of small skin blemishes, etc... Other quality than sharpness can be desirable in lenses.
Logged

theguywitha645d

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 970
Re: DIGITAL Medium Format photography is almost as moribund???
« Reply #172 on: March 07, 2013, 01:08:54 pm »

This is not intended to fan any format war.

I don't know if this is true, mainly because my experience with certain M mount lenses.  The Summicrons I have experience with never appeared flat, in fact are very close to Mamiya 7 images of the same subject matter.  The Zeiss ZM mount 28 2.8 has more contrast than any lens I've ever used.  In any format.  It is also one of the sharpest lenses I've ever used.

I think "flatness" is more a function of shooting conditions (lighting, focal length, F stop, distance to subject), the sensor, and any post work put into a file (or the default curve of film). 

This is why I stated you could take the lens format things so far. You are also comparing Leica optics which tend toward contrast anyway to Japanese optics that tend toward resolving power and two lenses from different formats. There is a whole sliding scale, which is why I said you can take things so far.

Oddly enough, you can see contrast difference in Erik's posts. Look at the marble pattern and it has a bit more pop in the Hasselblad image. I noticed this comparing a m4/3 lens with the same focal length of a CV 35mm lens--the m4/3 had more resolution and the 35mm had more contrast. This has nothing to do with lighting or such. It is an actual property of the optics.
Logged

ErikKaffehr

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 11311
    • Echophoto
A few comments...
« Reply #173 on: March 07, 2013, 02:09:53 pm »

Hi,

I think the statement the we can have either have high contrast or good resolution is an old myth. My guess is that it comes from old times when antireflex coating was rare. God resolution needed many lens surfaces, but using more surfaces resulted in more flare. Now days I don't think this applies.

I also don't think that it is not possible to make large format lenses with high resolution. It's just a question of cost. Larger formats were mostly used at small apertures and lens constructions were designed to reach optimum performance at the commonly used apertures. It would be possible to design better lenses, but the advantage would be negated by diffraction anyway. (I did not find pixel pitch data for the H3D-31, so I used H4D-31 data instead.)

Rodenstock's HR lenses have impressive MTF plots, if they are fake or real, I don't know.


When we compare a 36 MP Nikon D800 with a 31 MP Hasselblad we need to keep in mind that the Hasselblad's larger pixels make much less demand on the lens than the Nikon's smaller pixels. The enclosed MTF plot is calculated on a test shot from a 85/1.4 lens on Nikon D800E by Michael Reichmann. In this case we can see that this lens would transfer about 13% contrast at Nyquist limit on Nikon, would we put the same lens on the Hassy, it would transfer around 33%, because of the larger pixels. So if a Nikon D800E comes even close to the Hasselblad H4D-31 at the pixel level, it is quite an engineering feat! If we add that the D800 has OLP filtering and the Hasselblad does not the demand on the Nikon lens is even higher.

I have seen a paper from Schneider stating that MTF at Nyquist should be below 20% to avoid excessive moiré. This indicates that the 31MP Hasselblad would have problems with moiré but not the 36 MP Nikon.

Best regards
Erik
« Last Edit: March 07, 2013, 02:12:25 pm by ErikKaffehr »
Logged
Erik Kaffehr
 

Guy Mancuso

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 1133
    • http://forum.getdpi.com/forum/index.php
Re: DIGITAL Medium Format photography is almost as moribund???
« Reply #174 on: March 07, 2013, 02:29:37 pm »

What I see a lot when I did my comparisons to the IQ 160 and 140 backs with my D800E is Nikon cannot handle the specular highlights anywhere near the bigger backs. That was pretty obvious outside the normal things we look for like micro contrast/ tonal range/color and such which the backs won those races. I still believe also the differences in sensors CCD and CMOS as they just handle data completely different. End of day no matter how I sliced the cheese and threw everything at those tests MF still won the game but Nikon has done a very nice job with upping its game. You have to give them credit for that. I think a Version 2 of this sensor or some more advanced technology would help it more no doubt but this VS that stuff I am so far over it that I dont read any of it anymore and just go about and getting work done. There are a lot of downsides which never get mentioned here on the Nikon and trust me its not perfect by any stretch. I use 5 different brands of lenses to get the best images i can from it and frankly that is not right Nikon cannot get a damn good wide angle out the door when a 500 dollar Samyang 14mm distorts like a banchee but is damn sharp. Clean up the distortion and its a damn nice lens. Really whats Nikons excuse , so hearing how great it is only half the story.

MF is a niche market for a select photographers that want to work in that medium regardless of costs, hassle and limitations. Good for those folks they like to work at getting the best they can from it. I loved the tech cam and it for me was a load of fun to shoot and after 40 years your looking for fun trust me. LOL

People love Leica M cams which is maybe the worst focusing, framing cams on the planet. But folks love shooting them and frankly I do too. The day these systems are perfect is the day humans wont be shooting them.
Logged
[url=http://forum.getdpi.com/forum/showt

FredBGG

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 1630
Re: DIGITAL Medium Format photography is almost as moribund???
« Reply #175 on: March 07, 2013, 02:32:35 pm »

Hi Fred,
I don't think so. I would normally scales the images so short size of the image would match, but in this case the image size are so close that I don't think it really matters, Nikon is 4912 and Hassy is 4872. Resizing affects image quality, BTW.
Best regards
Erik


But if you are making a visual comparison you need to match the scale at which the subject is displayed. This will also give a better indication of what a print will look like if it's printed very large.
Resizing will effect the quality slightly.

If you scale down a lot it helps, but if you scale just a little it makes either little difference or is detrimental.

In this case the Nikon was scaled down very slightly so no gain ...if anything a little loss as I also rotated the image so as to make the comparison
line up better.

IF you look very carefully at the animated gif you can see that one is sharper
than the other.... but only very slightly.

It's the Nikon one and it was shot with a 14 to 24mm zoom. Yes the 14 to 24 mm zoom is very sharp but that just adds to the advantages of
the Nikon and other 35mm systems. It would also explain why many architectural photographers are using 35mm DSLRs more and more.


  
« Last Edit: March 08, 2013, 05:21:55 am by FredBGG »
Logged

ErikKaffehr

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 11311
    • Echophoto
Re: DIGITAL Medium Format photography is almost as moribund???
« Reply #176 on: March 07, 2013, 02:40:03 pm »

Guy,

I have great respect for your photography, but I'm pretty sure that you are given false information. Both CCDs and CMOS devices are linear, when they clip they clip.

My guess is that MFD tends to either underexpose by default, or that the raw converter is better at reconstructing lost channel data.

I can very well see that it is your practical experience that MF retains highlights better, but that is simply not feasible unless some cheating is involved.

On the other hand, some cheating is OK, it is really results that matters. Except, that there are some techy types like me who want to understand what is behind what we see...

Best regards
Erik

What I see a lot when I did my comparisons to the IQ 160 and 140 backs with my D800E is Nikon cannot handle the specular highlights anywhere near the bigger backs. That was pretty obvious outside the normal things we look for like micro contrast/ tonal range/color and such which the backs won those races. I still believe also the differences in sensors CCD and CMOS as they just handle data completely different. End of day no matter how I sliced the cheese and threw everything at those tests MF still won the game but Nikon has done a very nice job with upping its game. You have to give them credit for that. I think a Version 2 of this sensor or some more advanced technology would help it more no doubt but this VS that stuff I am so far over it that I dont read any of it anymore and just go about and getting work done. There are a lot of downsides which never get mentioned here on the Nikon and trust me its not perfect by any stretch. I use 5 different brands of lenses to get the best images i can from it and frankly that is not right Nikon cannot get a damn good wide angle out the door when a 500 dollar Samyang 14mm distorts like a banchee but is damn sharp. Clean up the distortion and its a damn nice lens. Really whats Nikons excuse , so hearing how great it is only half the story.

MF is a niche market for a select photographers that want to work in that medium regardless of costs, hassle and limitations. Good for those folks they like to work at getting the best they can from it. I loved the tech cam and it for me was a load of fun to shoot and after 40 years your looking for fun trust me. LOL

People love Leica M cams which is maybe the worst focusing, framing cams on the planet. But folks love shooting them and frankly I do too. The day these systems are perfect is the day humans wont be shooting them.
Logged
Erik Kaffehr
 

Chris Barrett

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 730
    • www.christopherbarrett.net
Re: DIGITAL Medium Format photography is almost as moribund???
« Reply #177 on: March 07, 2013, 02:43:11 pm »



CB

ErikKaffehr

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 11311
    • Echophoto
Re: DIGITAL Medium Format photography is almost as moribund???
« Reply #178 on: March 07, 2013, 02:49:32 pm »

Hi,

I don't think that we need to have perfect comparisons. Why, because you can shot a slanted wedge and have much better comparison. Also, I don't think we need to adjust image size. Any small differences can be adjusted in post.

I would say that Jerome's test gives good info for anyone interested in buying an elder MFDB or a D800 and that the lenses are OK at large apertures. All that is good info.

Jerome also points out that Hasselblad's AF actually works.

Best regards
Erik

But if you are making a visual comparison you need to match the scale at which the subject is displayed. This will also give a better indication of what a print will look like if it's printed very large.
Resizing will effect the quality slightly.

If you scale down a lot it helps, but if you scale just a little it makes either little difference or is detrimental.

In this case the Nikon was scaled down very slightly so no gain ...if anything a little loss as I also rotated the image so as to make the comparison
line up better.

IF you look very carefully at the animated gif you can see that one is sharper
than the other.... but only very slightly.

It's the Nikon one and it was shot with a 14 to 24mm zoom. Yes the 14 to 24 mm zoom is very sharp but that just adds to the advantages of
the Nikon. It would also explain why many architectural photographers are using 35mm DSLRs more and more.


  
Logged
Erik Kaffehr
 

theguywitha645d

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 970
Re: A few comments...
« Reply #179 on: March 07, 2013, 03:08:12 pm »

Hi,

I think the statement the we can have either have high contrast or good resolution is an old myth. My guess is that it comes from old times when antireflex coating was rare. God resolution needed many lens surfaces, but using more surfaces resulted in more flare. Now days I don't think this applies.

It has nothing to do with flare. Since I have seen the effect myself in modern multicoated lenses, it is hardly a myth.

BTW, I did not say it was either/or. I stated, you cannot optimize a lens for both. That does not mean lens design cannot improve on both, but the qualities are mutually exclusive. When designing a lens, you take the format into consideration and so make design decisions based on that.
Logged
Pages: 1 ... 7 8 [9] 10 11 ... 16   Go Up