user manual for Mamiya 645 extension tubes?

[Greg_E]

Does anyone know where I might find a user manual for the manual focus Mamiya 645 extension tubes? I looked around the Mamiya site but didn't find much beyond the magnification chart. I know they originally had some kind of user manual, but I'm not sure how much information was in that manual.

Thanks.

 

[max_ebb]

Hmm, I've never seen a user manual for extension tubes, and I've used a few of them on a few different cameras over the years. I could most likely answer any specific question(s) you might have.

I suspect that any question(s) you have would have something to do with the aperture. With some tubes, you have to stop down the aperture before you take the picture (fully manual). With some, the aperture stops down automatically when you take the picture, but you have to stop it down for metering if you have a metered finder (auto extension tube w/o meter coupling). Some are fully automatic with meter coupling, so you just use the camera as you normally would without the extension tube. Which type do you have? If you're not sure, it's pretty easy to determine.

 

[ben-s]

Hi Greg,
I have extention tubes no.1&3s.
as far as I know there was no manual with them - they are coupled for both metering and auto stopdown.

 

[Greg_E]

OK, in the magnification chart that Mamiya has, it only lists a few lenses. I did a little playing last night and found that some lenses did not work. Among those that were not great were the 210mm and my 30mm. The 30mm wanted to focus everything right on the objective lens (or behind it). The 210 worked but didn't provide much magnification. I also tried my 500mm to see if it would focus closer, but it didn't seem to work at all. Best results were with the 55mm up to the 110mm (didn't try my 150mm and don't own the 45mm). Would the 45mm still work well without having to put the object in contact with the glass? Since it isn't listed in the chart, I have a feeling the answer might be no. Really I just assumed that they would come with instructions listing all the lenses that worked with the different tubes. I have all 3 tubes which gives me a total of +6 (+1, +2, +3). I bought these because they were the one thing I've never worked with, and thought that to have a complete kit they were something I needed. And every once in a while I find that I can't focus quite close enough with a particular lens, and thought if I just put an extension on the lens that would do the job. Those times when you get just inside the minimum working distance of the lens you need, and can't take a step back to get things in focus (+1?). I've used close focus lenses in the past, and thought the tubes would be a little more similar, but of higher quality.

 

[max_ebb]

When using macro tubes, short lenses focus much closer than long lenses. When using a wide angle lens with a macro tube, it's generally better to set the lens focus to somewhere near the infinity end of the range, so you don't have to have the lens almost touching the subject. Also, when you get really close to the subject, it is smetimes not possible to focus using the lens focusing ring because changing the focus on the lens causes the distance from the lens to the subject to change as you are trying to focus. When using macro tubes, I generally always set the lens focus to where I want it, and then focus by moving the camera closer/farther from the subject (I always use either a copy stand or a tripod when I use macro tubes).

 

[reellis67]

There is a manual for these, but I don't have one. I did, however, find it online once, although I can't find the link right now. Basicaly, you can attach these to any lens up to the 150mm - above that, according to my notes from the online manual, vignetting will occur(??). I also have the following exposure adjustments.

80mm lens: #1 add 1/3 stop, #2 add 2/3 stop, #3 add 1 stop
55mm lens: #1 add 1/2 stop, #2 add 1 stop, #3 add 1 2/3 stops

Sorry I don't have more info, but at least that's something...

- Randy

 

[reellis67]

I just posted this page, although it needs some work it should give you some info in addition to what I already posted.

http://www.redisonellis.com/m645tubes.html

- Randy

 

[Greg_E]

Thanks, the exposure comp is very valuable. Is it fair to say that with longer extensions I can just add up all the different compensations? EX. 80mm lens with all three tubes would be two stops compensation? That was one thing that really baffled me about the meter connection. I thought there would be some kind of bend to get the meter aligned with the f-stop for proper metering, but they are just straight through.

 

[max_ebb]

With through the lens metering (using a metered finder), you don't need to make any exposure adjustments since it's already metering through the extension tubes. The exposure adjustments are for when you're using a seperate hand held meter. The only time I use my metered finder is for macro shots, other than that I prefer using a spot meter.

 

[reellis67]

That's my understanding, yes. It's like using a large format camera, the farther the bellows extends the lens from the film plane, the more expsure is needed, so adding the amount of compensation for multiple tubes *should* give you the proper exposure adjustments. I have not tested all the settings above because I only have the #1 tube, but I believe them to be correct.

- Randy

 

[reellis67]

Greg,

I extrapolated the way these numbers were calculated (using the bellows extension formula) and found that by adding rings you need to add *more* compensation than you would get by just adding the individual factors together (due to squaring in the formula). I updated that web page with the results, but it should be noted that I am *assuming* this is the correct way to calculate these figures.

- Randy

 

[Greg_E]

Thanks, it at least gives me a ballpark to start in. I guess I could just use the meter finders, but I truly like to use the waist level finder for most of what I shoot. And I can fine tune this with my digital back when I get to some testing. If I ever get to where I'm doing a lot of macro work, I'll probably buy the bellows extension and reversing rings (etc.).

 

[reellis67]

Hope you've got lots of disposable cash for that bellows. The last one I saw went for almost $500 US, without the dual cable release...

- Randy

 

[Greg_E]

Yeah, I saw that too. Maybe at that point I'll just build my own.

 

[Mike Té]

There is an instruction booklet

Hi, Greg.

I have an instruction manual for my extension tubes. You can buy it from Craig Camera, $15:

http://www.craigcamera.com/ib_m.htm

Item no. #MAM-182

Cheers.

 

[altair]

Any scanned copy of the M645 extension tube online? I'm having trouble attaching them correctly to my M645 Super body & lenses..that rotating ring & the need to align it with the aperture coupler pin is really driving me nuts! I screwed it up once & now my aperture coupler pin is kinda bent. Helpppp anyone?

 

[MattKing]

Any scanned copy of the M645 extension tube online? I'm having trouble attaching them correctly to my M645 Super body & lenses..that rotating ring & the need to align it with the aperture coupler pin is really driving me nuts! I screwed it up once & now my aperture coupler pin is kinda bent. Helpppp anyone?

Mike Butkus' site has one - I'd suggest sending him the requested donation.

http://www.cameramanuals.org/mamiya_pdf/mamiya_m645_auto_extension_rings.pdf

 

[altair]

MattKing: Thanks Matt. I've donated to Mr Butkus a couple of times in the past, and will do so again now. Thanks again.