Hasselblad HC 50MM

[BobDavid]

I am thinking about purchasing this lens for copying artwork on a copystand. I'd be using it for artwork that is larger than 24" X 36." Is the lens sharp corner to corner and is CA under control? Is there barrel or pincushion distortion?

[tom_l]

I am thinking about purchasing this lens for copying artwork on a copystand. I'd be using it for artwork that is larger than 24" X 36." Is the lens sharp corner to corner and is CA under control? Is there barrel or pincushion distortion?

i can't really help you with this lens, sorry, but

I would really consider using a longer lens than that, at least 80mm, even if the grid on the copystand may help you when correcting the distortion of any lens, short lenses should really only be used if there no other solution. If your camera if really high on your copystand (with a 80 oe 120mm), mirror vibration can be an issue.
I had the 60mm CF lens which as really not the best lens to use on the copystand. When artwork was larger than A2, i didn't use the copystand, but shot it vertically at the wall. Paintings tend to get longer and larger, but luckily the contemporary museums also get bigger and bigger.

The best reason to use a longer lens is lighting. With short lenses, it can be quite tricky to get rid of the reflections on oil paintings.

Tom

[BobDavid]

Thanks, Tom. I'm well aware of the issues you raised. I'm currently using a 72mm Schneider Digitar, which is hard to beat. Getting back to using the Hasselblad HC 50mm, for larger artworks, my copystand column is over 9 feet. I have my reasons for wanting to use the 50. My questions about that lens are purely in regard to its sharpness, CA, and linearity.

[Dustbak]

I have one, it is a great lens especially stopped down somewhat. I use it (amongst others) to do flat-styled clothing. Quite frankly I have never really scrutinized the corners or checked its distortion. For my purposes both are adequate.

I can make some test shots for you somewhere this weekend at different apertures of some flat stuff if you like?

[jjlphoto]

Why do you want to use a wide angle for flat art copy? 2x the normal lens is the rule of thumb for this sort of work. The 120/4 Macro is what you want. Macros also have a flatter field of focus and are designed to minimize any barrel/pincushion distortion.

[BobDavid]

Why do you want to use a wide angle for flat art copy? 2x the normal lens is the rule of thumb for this sort of work. The 120/4 Macro is what you want. Macros also have a flatter field of focus and are designed to minimize any barrel/pincushion distortion.

I don't have a high enough ceiling to accommodate a tall enough copystand column to handle photographing 4' X 3' artworks with a 120MM lens. If the Hasselblad 50MM HC lens is capable of taking a picture without linear distortion, CA, and is sharp stopped down to around f/11, what do I care about rules of thumb?

[David WM]

I use the HC50 on a H1, so I don't have the advantage of DAC. I find that I use about +1.0 of barrel distortion correction in PS, so there is a bit there. On the CA side, I use around +3 on the red/Cyan slider. I usually shoot F8 to F11.  This is not with close up work, so I expect that would be worse.

I think that if you were using this lens for copy work it would pay to be a part of the DAC system. But, as usual, test it for your usage needs.

Regards, David

I don't have a high enough ceiling to accommodate a tall enough copystand column to handle photographing 4' X 3' artworks with a 120MM lens. If the Hasselblad 50MM HC lens is capable of taking a picture without linear distortion, CA, and is sharp stopped down to around f/11, what do I care about rules of thumb?

[yaya]

I don't have a high enough ceiling to accommodate a tall enough copystand column to handle photographing 4' X 3' artworks with a 120MM lens. If the Hasselblad 50MM HC lens is capable of taking a picture without linear distortion, CA, and is sharp stopped down to around f/11, what do I care about rules of thumb?

80mm Macro from Schneider

Bit longer than 50mm but a true flat field, straight, macro lens. I've tested it with 56MP sensor and it comes fairly close to the APO-Symmar 90mm Macro on the AFi, which in my view the best copywork lens money can be spent on.

The HC50 in my view is really a compromise. If you have to use a wide-angle lens then perhaps you should look at a 47XL (Digitar or not) or maybe the Rodenstock 55mm HR.

Yair

[tom_l]

Thanks, Tom. I'm well aware of the issues you raised. I'm currently using a 72mm Schneider Digitar, which is hard to beat. Getting back to using the Hasselblad HC 50mm, for larger artworks, my copystand column is over 9 feet. I have my reasons for wanting to use the 50. My questions about that lens are purely in regard to its sharpness, CA, and linearity.

The Digitar 72mm is definitely my next lens. I have the 100mm Digitar already and it's and amazing lens. I only heard good thinks about the 72mm.
Good luck with your 50mm HC


Tom-

[Dustbak]

CA is a non-issue with DAC.

[jjlphoto]

I don't have a high enough ceiling to accommodate a tall enough copystand column to handle photographing 4' X 3' artworks with a 120MM lens. If the Hasselblad 50MM HC lens is capable of taking a picture without linear distortion, CA, and is sharp stopped down to around f/11, what do I care about rules of thumb?

If you are in too close with your lens, it will be difficult to control glare on the edges of the artwork nearest the copy lights, as you will be right in line with their angle of incidence.

Also, any deviations from perfect plumb will be more readily visible being in that close. Can you place the copy stand base right on the floor?

[BobDavid]

If you are in too close with your lens, it will be difficult to control glare on the edges of the artwork nearest the copy lights, as you will be right in line with their angle of incidence.

Also, any deviations from perfect plumb will be more readily visible being in that close. Can you place the copy stand base right on the floor?

For large flat artwork, 3'X 4' and larger, under cross polarized lighting, in a room with a black ceiling, floor, and walls, I don't see glare being a problem. All I am trying to ascertain is sharpness and linearity of the lens. I've been doing fine art repro for 20 years. My copystand column is over nine feet tall. I'm not concerned about glare, rules of thumb about focal length or any other comments other than the linearity qualities and sharpness of this lens.

[jjlphoto]

The data sheets show significant barrel distortion and more illumination fall-off on the HC50 as com pared to the 120 Macro. In fact, the distortion graph from the HC50 indicates that it suffers from the more complex mustache or gull-wing distortion, much more difficult to correct than a simple barrel or pincushion type of distortion.

[jjlphoto]

50HC on the left

[Cfranson]

The data sheets show significant barrel distortion and more illumination fall-off on the HC50 as com pared to the 120 Macro. In fact, the distortion graph from the HC50 indicates that it suffers from the more complex mustache or gull-wing distortion, much more difficult to correct than a simple barrel or pincushion type of distortion.

While we haven't tested the HC50, the HCD 28 also has mustache distortion which is easily and effectively corrected in Flexcolor/Phocus. I expect the 50 has received similar correction.

[BobDavid]

50HC on the left

Thank You! This is helpful.

[jjlphoto]

Thank You! This is helpful.

The full lens data sheets can be viewed at:
http://www.hasselbladusa.com/downloads/dat...s/h-system.aspx

The MTF graphs can help you decide which one resolves better, and in what areas across the imaging area.

A word of caution however, even with the distortion correctable in the RAW processing software as mentioned above, it is done by interpolation. And interpolation is interpolation. You might consider some tests to see if the results are satisfactory. I use LensFix from Kekus to fix linear distortion (it is based on the PanoTools formula). I use it as a Photoshop plug-in applied to my TIFF file after the RAW process. For my purposes, the results are fine. YMMV.

[David WM]

..... I use LensFix from Kekus to fix linear distortion (it is based on the PanoTools formula). .....

Does lensfix correct the moustache distortion, or do you know what programs might be best for this on a mac?

Regards, David

[dwdmguy]

I had to laugh Bob, it's always the same around here, you ask about one lens specifically and you get recommendations on why your using the wrong lens and you should be using the........ instead... Too funny.

[Jann Lipka]

Bob,
I' quite happy with Epaperpress PTLens - it works on Intel Macs only .
I use it for 35 mm H series lens and most of my Canon lenses .
Its based on PanoTools .


I would take a test shot with your lens and get its distortion calibrated and put into PTLens database .

http://www.epaperpress.com/ptlens/index.html


I think removing mustache distortion in Photoshop  is very difficult .
Lens distortion tool is no good at all , but maybe you could try some warping .

I would go with PTLens , but  you need some extra days for the calibration .
Tom Niemann , the author of PTLens is normally  fast with answering and his work .



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