[excanonfd]

The type of back is electrically coded. Therefor the length of the film.
No other difference! Lay them side by side and you will see different contacts.
(Since I have enough 120-Backs I've not tried to convert a 220-Back)

-Linus-

If I had both 120 and 220 backs my question would be a moot point, as I would have experimented with them myself, to see whether converting 220 back to accept 120 roll film is possible or not. You imply that you have both 120 and 220 film backs, why don't you experiment and prove once and for all whether this conversion is a urban myth or not. At the worst, it will cost you a roll of 120 film.

Thanks,

[rparmar]

I have read your blog about photography and cannot find the article on converting a 220 film back to accept a 120 roll film.

I have converted a back but have not run film through it, which is why I have been quiet on this issue. I do not want to propagate incorrect info. Shooting the film is no problem but there is too much stuff going on here at the moment for me to develop it.

Why not just describe the procedure here in the Pentax Forums, in this thread, where the information would be more relevant and much more likely to receive better welcome than your blog whose subjects' range beyond photography?

The opposite makes more sense. All my articles should be on my own blog and linked to from here. That way my own readers (significant numbers, BTW) do not miss out on anything.

But if you will look at my post count you will see that I have contributed much here that is not on my blog!

[excanonfd]

I have converted a back but have not run film through it, which is why I have been quiet on this issue. I do not want to propagate incorrect info. Shooting the film is no problem but there is too much stuff going on here at the moment for me to develop it.

Oh Ho!! Robin Parmar, the Myth Buster is about to make his debut! I'll be looking forward to your results. But seriously, between you mentioning the conversion of 220 back and visit your blog to read how, until your reply to this thread, about three months had passed. I was wondering if the 220 film back conversion thread had started, closed and been buried in obscurity, hence my query to you.

The opposite makes more sense. All my articles should be on my own blog and linked to from here. That way my own readers (significant numbers, BTW) do not miss out on anything.

This is the Pentax Forum, the root directory is "Pentax Medium Format: 645,6x7, 645D", and the subject in this sub-thread is converting a Pentax 645 format's 220 roll film back to accept 120 roll film. Need I say anything more?

But if you will look at my post count you will see that I have contributed much here that is not on my blog!

I don't wanna go there.

[GeneV]

I found the 645 to be easy to focus, and the manual focus variety is the one that is dirt cheap on Ebay. I'm going to learn to use that one before springing for any real money for the "n" models.

The processing is a bit of a problem. I used to do my own color processing when I shot lots of film, but it absolutely does not pay if you don't process a bunch of rolls at a time. You will pay more in the end than sending it off, but you may save time.

The accessories for this camera are so cheap that it hardly makes sense to fool around converting the backs. Last year, I ended up paying about $300 on Ebay for a body, 3 lenses, and 3 backs (including 1 220). The seller even threw in a dozen rolls of slightly out of date film.

[rparmar]

But seriously, between you mentioning the conversion of 220 back and visit your blog to read how, until your reply to this thread, about three months had passed. I was wondering if the 220 film back conversion thread had started, closed and been buried in obscurity, hence my query to you.

I did not say the info was on my blog. You misread what I actually wrote, which was "More info on this when I write it up for my blog" [emphasis added].

No timeline was stated. There are many other things I have also not done in the past three months -- trying to make a living as an artist is so killer. Everyone expects everything for free. I have a donation link on my blog and encourage people to use it. If I get donations towards a particular project I am a lot more likely to give it priority. I have 400 articles written as it is and dozens more in the pipeline... when time allows.

This is the Pentax Forum, the root directory is "Pentax Medium Format: 645,6x7, 645D", and the subject in this sub-thread is converting a Pentax 645 format's 220 roll film back to accept 120 roll film. Need I say anything more?

No, but you could say less. Or at least get the facts straight. The subject is in fact "Is the 645 hard to focus for a blind old guy?" This whole thing about converting the film insert is a small aside. But it's turning into a thread hijaak so I will write no more of it after setting the record straight in this post.

Apologies in advance if I have misinterpreted your sarcasm.

[GeneV]

On the original subject, I can state from this afternoon's experience, that a 645 is hard to focus if you don't adjust the diopter properly.

[excanonfd]

No, but you could say less. Or at least get the facts straight. The subject is in fact "Is the 645 hard to focus for a blind old guy?" This whole thing about converting the film insert is a small aside. But it's turning into a thread hijaak so I will write no more of it after setting the record straight in this post.

So, I am a thread hijacker now? Somehow it just doesn't seem all that ominous. I was reading another thread when I first joined, where some members of the community was discussing the conversion of 220 back to accept 120 film, but that discussion did not arrive at any conclusion. Then I started reading "Is the 645 hard to focus for a blind old guy?" thread, and you rparmar said, it can be done easily (your own words); come to my blog for information - so I did - but did not find anything. I could have asked for the information in the blog, but I decided the better venue to do so is the Pentax Forums. I believe the members of this community are more knowledgeable about anything Pentax, and would definitely be more interested in your findings or none, than your average blog readers.

I could have started another thread, but why? The forum is set up so that any new post in a dormant thread is bumped up to the top; anyone can take a look at the new post and if they have any facts, myths, or opinions on the subject, can chime in with a post or move on.

Thanks,

[excanonfd]

Greetings jbrowning,

I apologize for "hijacking" the thread...

If I may chip in my two cents worth, I may be in worse shape than you are and I have no problems manually focusing my 645 (so far). I had my cataract replacement surgery in my right eye done two years ago and after the surgery, the Doctor said "now you have 20/20 vision in your right eye". That may be true, but the replacement cataract lens is nowhere near as good as your natural yellowish sac of protein. Bright lights are troublesome, early dawn and late dusk vision has become more limited. If I was to describe my right eye as a camera lens, take an f-stop or two from either end of the said lens' aperture would be (I think) an apt comparison. But I am thankful that it is only cataract, not anything truly serious.

I think I can continue to manually focus the 645 accurately if I stick to prime lenses no slower than f2.8, with f4.0 and slower I will probably limit myself to shooting only under bright lighting conditions. Eventually I will buy an Beattie Intenscreen replacement focusing screen, which reportedly gains about 1 or more f-stop in screen brightness. Granted, I probably will have trouble focusing in very low light situations, but the days of staying up all night so I can shoot at the earliest light possible is long, long past. If you have an angle finder with 2x or higher magnification, you can use it as a focusing aid, similar to using a 6x-10x loupe against the ground glass on the large format cameras as a focusing aid.

I believe if I use every trick in the book to enhance focusing, I can manually focus my 645 for long time to come. Having said that, I will get the 645n at the earliest opportune moment.

Thanks,

[-Linus-]

On the right you see 120 Back, on the left a 220.
You just need a small Philips Screwdriver and mount the plastic part in the middle the other way round. The golden contact is conected to the springs at the pressure plate. When they are connected to ground the camera stops rewinding the film.
There is no focal plane issue.

-Linus-

[Nesster]

Thank you Linus, saves me the trouble. In case anyone's having a hard time finding the difference: on the left in the photo, in the middle part, there's a philips screwhead - and you see the plastic has a finger extending downward, on the left. On the right side, the same philips screw - and no finger pointing down (it in fact points up, on the right, which you may just be able to make out). That, and the label on the insert, is the only difference.

I wish it were, but it isn't a middle finger

[rparmar]

So, I am a thread hijacker now?

I was talking of myself, since I was the one to bring up the issue.