645 digital back on a large format camera

[Neo]

Hi guys,

Just want to find out if there's anyone who used a 645 digital back on a LF camera. The applications I'm interested in includes still-life, interior and architecture photography.

Given that the 645 back is less than half the 4x5" film area, I have plenty of room to shift without running out of image circle area. I'm intending to get a 150mm lens for the LF for shooting still-life (mainly table-top product photography). Any comments on that?

What is more perplexing is the choice of lens for interior and architecture. Assuming that I'm looking for a lens that approximates 28mm in the 35mm format, how do I calculate the right focal length for the large format lens, given that the exposure area is 645 rather than the full 4x5"?

My own calculations indicate that a 47mm large format lens will provide 35mm focal length field-of-view for 35mm-format, when mounting a 645 back which adds a 2.35x crop factor. Is that correct?

 

[pchong]

Hi Neo, I don't have any personal experience using a 645 back on a LF view camera, but have discussed this numerous times with various people. Some thoughts:

It seems that the new digital backs will place very stringent demands on stability of the front and rear standards...more so than film does. Firstly, the backs are much heavier than film. Secondly, the adjustments which are sufficient resolution for film, will need to be finer for digital.

Many people will find focussing and judging adjustments (tilt, swings especially) on the LF ground glass very difficult. Examining the rather dim, and small patch which corresponds to the 6cm x 4.5cm (its actually smaller as 645 digital sensors are a crop of the film 645 except for P65+ and the H4D60 which are almost full frame 645. Of course alternatives for 4x5 view cameras are cameras built for medium format 6x9, like Arca Swiss 6x9, Linhof M679, or Rollei X-Act. 6x9 film is still twice the area of 645 film.) area will prove difficult. Film is less critical of absolute focus, emulsion has a finite thickness, which I understand are thicker than sensor pitch of today's digital backs. With photo sensors the size of 6 microns, digital media is more critical of absolute focus.

For interior and architecture, you might be able to stitch the frames using a stitching back adapter. But for table top macro, you will have the sharpest part of the lens, but as per above, judging critical focus is not going to be easy. This may be helped with live view, and focussing on the computer monitor.

Hi guys,

Just want to find out if there's anyone who used a 645 digital back on a LF camera. The applications I'm interested in includes still-life, interior and architecture photography.

Given that the 645 back is less than half the 4x5" film area, I have plenty of room to shift without running out of image circle area. I'm intending to get a 150mm lens for the LF for shooting still-life (mainly table-top product photography). Any comments on that?

What is more perplexing is the choice of lens for interior and architecture. Assuming that I'm looking for a lens that approximates 28mm in the 35mm format, how do I calculate the right focal length for the large format lens, given that the exposure area is 645 rather than the full 4x5"?

My own calculations indicate that a 47mm large format lens will provide 35mm focal length field-of-view for 35mm-format, when mounting a 645 back which adds a 2.35x crop factor. Is that correct?

 

[Neo]

Hi Peter,

Thanks for the very enlightening answers! I figured that digital will be very demanding on the focusing of a LF camera, but I intend to tether the back to a computer so I can see the focus errors and re-adjust and shoot if I have to. The wonders of digital! I remember the days where I shot sheets of 4x5, only to find out days later that the focus was off (probably when I was inserting the film holders on the flimsy rear standards... or was it the tripod? Hmm....)

You brought up a good point about stitching the digital exposures for interior and architecture shots. That will go a long way in solving the dilemma of using a 645 sized sensor on a 4x5-format lens. :thumbsup:

 

[pchong]

Neo, I think the problem is more than just ability to judge critical focus...which is easily solved with live view when shooting tethered.

From the readings I have done, apparently digital presents significant challenges to the precision and accuracy of the zero points, the ability for adjustments to be sufficiently precise (in small enough steps) to maintain critical focus and subsequently stability of the standards. Meaning, most view cameras, except for those designed for digital (Sinar P3, Rollei X-act2, Cambo Ultima, Arca Swiss Monolith, Linhof 679) are not able to have precision in microadjustments to allow just so focus, and after achieving critical focus, locking the standards will cause shifts which are large enough to screw up critical focus.

For landscape and architecture, most have switched to technical cameras like Alpa, Cambo Ultrawide, Arca Swiss and the like, which is precisely machined for parallel front and rear standards, and allow micrometric adjustment of rise/fall and shifts. These cameras also allow for stitching using digital backs.

Hi Peter,

Thanks for the very enlightening answers! I figured that digital will be very demanding on the focusing of a LF camera, but I intend to tether the back to a computer so I can see the focus errors and re-adjust and shoot if I have to. The wonders of digital! I remember the days where I shot sheets of 4x5, only to find out days later that the focus was off (probably when I was inserting the film holders on the flimsy rear standards... or was it the tripod? Hmm....)

You brought up a good point about stitching the digital exposures for interior and architecture shots. That will go a long way in solving the dilemma of using a 645 sized sensor on a 4x5-format lens. :thumbsup:

 

[Neo]

After more research on using a MFDB on a LF camera, I probably will drop the idea. First of all, it seems pretty inconvenient to set up the LF camera with the MFDB. And more importantly, the field of view for the LF lenses are significantly cropped by the relatively smallish 645 sensor size. To do the stitch technique, the sliding back costs about the same as a pre-owned 22MP MFDB! I think I'll live with the perspective effect and do the correction in Photoshop....

 

[pchong]

Neo, you can consider Arcbody/Flexbody/ or PC Mutar with a CFV back on the 500 body, or H1 and H2. Or go for H3D or H4D with HTS1.5. Allows some adjustment, enough for interiors and architecture, but in my last trial, not sufficient for tabletop and macro.

 

[Neo]

Hi Peter,

Thanks for the suggestions. Very useful tips once again! I did consider these options, especially the Flexbody since I already have access to the V-system as well as a Phase One back (with V-mount). However, I'm concerned about the limited degree of tilt it offers, but I'll do more research on whether it's good enough for desktop photography.

By the way, I came across something which may be of interest to CSers. The Cambo X2-Pro lets you achieve tilt-shift capability (front standards movements) with your 35mm DSLRs. Not expensive considering you are able to use a wide-range of existing lenses! Check it out at the following URL:

http://www.cambo.com/Html/products_photo/set01/english/internet/Item752.html

 

[agape01]

I have experience shooting with MF digital back on a LF setup.

For table top, 150 is a little long. The best lens to use it would be a 90mm. You would have to take the crop factor into consideration.

Now about architecture, you may want the Schneider 28mm digitar lens as it would be wide enough for most architecture shots that you are thinking of doing. Alternatively, a 47mm would also be a pretty good choice to have.

For your info, the setup that I have experience with is a Leaf Aptus 22MP on a Toyo LF cam tethered to a desktop computer shot in studio. I also have experience with a phase one back too. I prefer phase one than leaf.

Let me know if you got any more questions....

 

[agape01]

Hi Peter,

Thanks for the suggestions. Very useful tips once again! I did consider these options, especially the Flexbody since I already have access to the V-system as well as a Phase One back (with V-mount). However, I'm concerned about the limited degree of tilt it offers, but I'll do more research on whether it's good enough for desktop photography.

By the way, I came across something which may be of interest to CSers. The Cambo X2-Pro lets you achieve tilt-shift capability (front standards movements) with your 35mm DSLRs. Not expensive considering you are able to use a wide-range of existing lenses! Check it out at the following URL:

http://www.cambo.com/Html/products_photo/set01/english/internet/Item752.html

Actually between a Cambo X2-Pro, I prefer a Horseman LD system.

 

[giantcanopy]

After more research on using a MFDB on a LF camera, I probably will drop the idea. First of all, it seems pretty inconvenient to set up the LF camera with the MFDB. And more importantly, the field of view for the LF lenses are significantly cropped by the relatively smallish 645 sensor size. To do the stitch technique, the sliding back costs about the same as a pre-owned 22MP MFDB! I think I'll live with the perspective effect and do the correction in Photoshop....

Hi Neo , i am not sure if this helps as an alternative
Zork offers some interesting gadgets for shift work
http://www.zoerk.com/pages/p_pshift.htm

" ProSA-P67 uses lenses from the Pentax 67 system for shift on 6x4.5 format cameras (Mamiya, Contax, Pentax, etc.) "

ryan

 

[Neo]

Hi Ryan,

Thanks for the heads up on Zork. It looks really good... probably what I need (view camera movement on MF camera). Since I'm using a 503CW, I think I'll need the Pro Shift Adapter plus the Multi Focus System. I'll email them with my query, and post their replies so that anyone else in the same predicament can share the solution.

 

[lkkang]

Hi Neo , i am not sure if this helps as an alternative
Zork offers some interesting gadgets for shift work
http://www.zoerk.com/pages/p_pshift.htm

" ProSA-P67 uses lenses from the Pentax 67 system for shift on 6x4.5 format cameras (Mamiya, Contax, Pentax, etc.) "

ryan

hi Ryan,

I have asked zoerk for a quotation for the ProSA-P67. and the pricing is :sweat:

The price for this adapter is € 850,-- + € 50,-- for shipping. On the Mamiya 645 AF camera body is w.o. problems, on the Mamiya 645 Super touch the plate of our adapter the part of the camera on which is the brand name Mamiya. Payment in advance to our banking account. We have no credit cards.
Kind regards


H. Zörkendörfer


Zörkendörfer Film & Fototechnik
Westendstr. 125
D 80339 München
Tel. +49.89.508568
Fax +49.89.504405
info@zoerk.com
www.zoerk.com

if you buy one, let me know.. :heart:

Billy.

 

[beanbean]

Hi Agape, could you elaborate more on why you prefer the horseman LD over the Cambo X2-pro?

 

[agape01]

I think that it is easier to see the shot of the setup...

First, I already had a Horseman shooting film, so all I had to do was to get the bag bellows to mount my DSLR on it. 2ndly, Horsemen are easier to use as it is so controllable with less dials. Lastly, I guess it is personal preference.

Cambo X2 on the hand I have no experience with them but for me to buy one, it would costs me more. I prefer to use what I have and upgrade from there rather than getting something new.

Having said that, they all are able to do the same thing.

 

[Neo]

Hi Agape,

Just to add on... I think the Horseman also has rear standards movements compared to the Cambo, which is restricted to front standards movements only.

 

[beanbean]

Hi Neo, please indulge my lack of knowledge. Having never used these technical cameras, the only advantage to rear standard movements that I can think of is that the rear movement provides extra movement should the front movements be insufficient. Is that correct? Are there other advantages that I'm not aware of?

 

[Neo]

Hi Beanbean,

The front and rear movements in a view camera does very different functions. The front standards control the focus plane with the tilt (vertical swing) or swivel (horizontal) swing function, allowing you to maximize or minimize the depth of field.

On the other hand, the rear standard movements control the perspective of the image. By tilting or swiveling the rear standards, you can change the way the subject is photographed in terms of perspective. The function is very much like transforming a subject in Photoshop using the "Transform>Perspective" command.

 

[beanbean]

Of course! How could I miss that. Yes, I understand how shifting/tilting the rear standard affects perspectives. Thanks!

Anyway, I'm also very interested in interior/architectural photography. Perhaps we could go shoot together sometime.

Meanwhile, any idea on how much either the cambo x2-pro or horseman LD costs?

 

[Neo]

If I'm not wrong, a Horseman LD costs $3.3k, and a Cambo X2 costs $2.8k...

Horseman LD
http://www.komamura.co.jp/e/digital/LD.html

Cambo X2 Pro
http://www.cambo.com/Html/products_photo/set01/english/internet/Item752.html

 

[franxon]

Hi Neo, glad to find alike minds here!

I have no experience with a digital back on a view camera. But I know for fact that many pros are doing it everyday. So really, if you have the means, by all means! It could only remain as a dream to me unless I strike TOTO.

This article sums it up nicely IMO: http://www.luminous-landscape.com/reviews/cameras/digital-view.shtml

Movements on TS lenses and Arcbody/Flexbody are limited.