[stefie]

Hi everyone

I recently bought an Asahi Pentax 6x7 and have received the scans from my test roll.

The aspect ratio of the images is 70 x 57.27mm rather than the standard 70 x 50mm. They seem cropped on the longest side, according to my memory of what I saw in the viewfinder when taking the shots. I was using 120 Kodak Portra, if that's useful to know.

Does anyone know what's going on here?

Thank you!

Update: I've measured the pentaprism and the shutter curtain and they are 7x5.5cm - does that sound right?

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Last edited by stefie; 10-15-2020 at 03:32 AM.

[35mmfilmfan]

How do the scans compare with the actual negatives ? Have the scans been cropped, or is the anomaly present on the negs as well ?

[Lord Lucan]

The aspect ratio of the images is 70 x 57.27mm rather than the standard 70 x 50mm.

70x50 is not a standard. Perhaps you meant to refer to the nominal 70x60mm? 6x7 (cm) was always a misnomer, there is hardly room on 120 film for 60mm wide images anyway; it is only 61mm wide. The picture area on my negs is 70x55mm, the same as Pentax themselves say in their brochures :

http://www.lucan.org.uk/Photos/67_system_brochure.pdf

[stefie]

How do the scans compare with the actual negatives ? Have the scans been cropped, or is the anomaly present on the negs as well ?

I'm waiting for the negatives to be returned in the mail, but yes, hopefully that should shed some light.

[stefie]

70x50 is not a standard. Perhaps you meant to refer to the nominal 70x60mm? 6x7 (cm) was always a misnomer, there is hardly room on 120 film for 60mm wide images anyway; it is only 61mm wide. The picture area on my negs is 70x55mm, the same as Pentax themselves say in their brochures :

http://www.lucan.org.uk/Photos/67_system_brochure.pdf

Perhaps I should have said 4:5 aspect ratio.

Here are one of the scans to give a clearer idea.:
PentaxForums.com

[ProfessorBuzz]

My 67 II gives 57x70mm negs.

[Wheatfield]

Perhaps I should have said 4:5 aspect ratio.

The 6x7 format isn't a perfect 4x5 format.

[Silent Street]

Notwithstanding quibble about the aspect ratio, or lack of conformity to one as such, the scan is lacking in quality.


The 6x7 format is rounded out from 70x55, seemingly because it is convenient rather than meaningful to beginners. 6x7 negatives and transparencies will be cropped around the edges somewhat during the scanning process, unless you have specified full-frame in the scanning jobsheet, which means the entire frame, not through the negative carrier or mount of a slide.

The sample does not look to be in 4:5 ratio to me.

[stefie]

Notwithstanding quibble about the aspect ratio, or lack of conformity to one as such, the scan is lacking in quality.


The 6x7 format is rounded out from 70x55, seemingly because it is convenient rather than meaningful to beginners. 6x7 negatives and transparencies will be cropped around the edges somewhat during the scanning process, unless you have specified full-frame in the scanning jobsheet, which means the entire frame, not through the negative carrier or mount of a slide.

The sample does not look to be in 4:5 ratio to me.

Thank you, this is really helpful. Yes, it seems that the negatives weren't scanned full-frame. I received a response from the facilities I used and they have confirmed that there is a crop factor of 3-5% with their scanner, which I'm really surprised by. I'm new to medium format so perhaps I'm being naive, but I would assume that a business specialising in film processing and printing (and selling analogue cameras) would have the capability to scan full-frame 6x7.

[Wheatfield]

Thank you, this is really helpful. Yes, it seems that the negatives weren't scanned full-frame. I received a response from the facilities I used and they have confirmed that there is a crop factor of 3-5% with their scanner, which I'm really surprised by. I'm new to medium format so perhaps I'm being naive, but I would assume that a business specialising in film processing and printing (and selling analogue cameras) would have the capability to scan full-frame 6x7.

Unfortunately, this is not the case. There has always been cropping involved in production film handling, whether optical printing or digital scanning. In order for film to move through the equipment without binding and getting damaged, there has to be some play in the film transport. Consequently, there also has to be some cropping so that if the film has moved entirely to the top of the printer frame, the bottom of the printed/scanned image isn't showing the film edge.
When I was running my custom printing lab, I had a few neg carriers that I had filed out to allow 100% printing of the frame, but they were useless for production work.
As long as the customer was OK with seeing the edge writing, I only charged double. If the customer wanted to see 100% of the image with no bleed into the non image area, I charged upwards of 10 times the regular printing cost for proof prints, payable in advance with no refunds, 5 times the regular cost for 5x7 or larger, again payable in advance with no refunds.
Too many people would change their minds after seeing how little difference it made and would try to renege on the contract.

I suspect with commercial film scanning, it isn't even possible to do a full frame scan. It might be something one could do with a flatbed scanner that is capable of negative scanning, but those aren't what one will find in a commercial lab.

[Silent Street]

I suspect with commercial film scanning, it isn't even possible to do a full frame scan

If you mean commercial, 'High Street' facilities, that would be correct: they do not have the time nor expertise to go down the path of detail. Pro labs most certainly know the meaning of full-frame and that's exactly what one gets when it is put down on the jobsheet.


____________________________________________________________

perhaps I'm being naive, but I would assume that a business specialising in film processing and printing (and selling analogue cameras) would have the capability to scan full-frame 6x7.

It sounds to me that you're film and scanning has been done at a High Street facility, rather than professional lab? There is a big difference. And one of the bigger ones is cost. And a lack of shiny display cases showing off fancy cameras. There might be a fridge in a few with a delightful assortment of well-known and obscure films, too. Experience and knowledge will put you in good steed dealing with the pro labs, where generally the client is expected to have a working knowledge of the end product he or she wants, and knows how much it costs.

[Lord Lucan]

High Street' facilities ... do not have the time nor expertise to go down the path of detail. Pro labs most certainly know the meaning of full-frame

I don't doubt what you say, but as the camera manages to expose the area it does while holding the film flat, I don't understand why a scanner cannot also be made to do so, even without close attention by the operator.

[Wheatfield]

I don't doubt what you say, but as the camera manages to expose the area it does while holding the film flat, I don't understand why a scanner cannot also be made to do so, even without close attention by the operator.

You have probably never worked with commercial photo finishing equipment.

[leekil]

I don't doubt what you say, but as the camera manages to expose the area it does while holding the film flat, I don't understand why a scanner cannot also be made to do so, even without close attention by the operator.

The camera has a solid pressure plate holding the film flat, as well as the spooled film on either side holding it tight. With a film scanner, the part you want to scan has to be fully exposed so light can pass through it. It's different mechanisms. In theory you could have a film holder that extends high on the top and bottom, but when you get to the end of a roll or negative strip. there would be little to keep it flat on the third side, if that type of thing were employed.

Maybe with a drum scan it would be easy to do what you want, as I believe the negatives are adhered to the drum with a liquid, but that's a lot more work and therefore more expensive.

[weverka]

Hi everyone

I recently bought an Asahi Pentax 6x7 and have received the scans from my test roll.

The aspect ratio of the images is 70 x 57.27mm rather than the standard 70 x 50mm. They seem cropped on the longest side, according to my memory of what I saw in the viewfinder when taking the shots. I was using 120 Kodak Portra, if that's useful to know.

Does anyone know what's going on here?

Thank you!

Update: I've measured the pentaprism and the shutter curtain and they are 7x5.5cm - does that sound right?

I was never happy with the scans that are offered with film development. The standard resolution they offer is no where near the resolution of a slow medium format film.

Have you considered scanning the negatives yourself? Or better yet, go from negative prints, or positive to projection display without ever digitizing it.