Exposure Comp for TLR's?

bvy · Dec 24, 2017

Here's something I read about recently. It seems some Mamiya TLR's have exposure compensation marks for close focusing. I never even considered it for my Yashica Mat 124G (80mm lens) -- the only "serious" TLR I own. For portraits I focus no closer than around 4 to 5 feet.

But I've only every shot black and white film and metered using Sunny 16. Until recently. I have a backlog of Provia that I've shot in it this year, but I haven't developed any of it. I also used an incident meter for these. Now I'm wondering if I shouldn't ask to have these pushed half a stop or more. Or am I splitting hairs? Plan at the moment is to process just one of the rolls normally and see how it looks...

MattKing · Dec 24, 2017

Four feet is 1200 mm.
That is 15 times the focal length of your lens.
You basically don't need to worry about exposure compensation until the distance from camera to subject is less than 8 times the focal length of the lens.
The lens-extension exposure dial in the Kodak Master Photoguide is your friend .

David Brown · Dec 24, 2017

bvy said:
I'm wondering if I shouldn't ask to have these pushed half a stop or more.

No.

The Mamiya TLRs have exposure comp scales because they have built in bellows. It's only when one cranks the bellows way out for close-up (macro) that the exposure compensation becomes a factor. Rolleis, Autocords, Yashicas, etc. do not focus that close, and so it is not a concern.

BMbikerider · Dec 24, 2017

The extension available with the bellows on a Mamiyaflex is far greater than any other TLR. The normal focusing movement of cameras such as Rollieflex and Yashicamat is so small that any difference is covered by the film latitude - perhaps less than 1/4 stop and that can be incurred with a mal-adjusted meter.

etn · Dec 25, 2017

The Hasselblad Historical site has a very thorough explanation about this. Scroll down to the very bottom of the page for an online exposure compensation calculator. (Although Hassy-centric, the calculator will work for your TLR.)
http://www.hasselbladhistorical.eu/HT/HTComp.aspx

In practice, when you focus closer, the film receives a tiny fraction less light. The difference is very minimal unless you reach macro range. As a matter of fact, the inaccuracies of the shutter are much greater than any exposure compensation you will ever need in normal shooting (so to speak). So, no need to worry about anything here.
Note that an exposure compensation is only needed when doing macro by extending the lens to film distance. No exposure compensation is required if you use a close-up lens.

Hope this helps

Etienne

bvy · Dec 26, 2017

Thanks everyone. I worked out the same math as best I could without the camera (I sent it off for CLA), and couldn't justify it either. Seeing the picture of the Mamiya above, I didn't realize it was capable of such close focusing (long draw). Makes sense now.

jim10219 · Dec 26, 2017

Yeah, just about every other TLR I've seen focus the lenses using a linked helicoil which moves the internal lens elements, much like your standard SLR or rangefinder camera. The Mamiya TLR's use static lenses that don't focus internally, so you have to focus them by moving the lens board back and forth on a rack connected with bellows, much like on a large format camera. This is also the reason why the Mamiya TLR's are the only ones (that I know of) that have interchangeable lenses. So you gain the ability to switch lenses at the cost of weight, bulk, and bellows compensation worries.

Ian Grant · Dec 26, 2017

bvy said:
Thanks everyone. I worked out the same math as best I could without the camera (I sent it off for CLA), and couldn't justify it either. Seeing the picture of the Mamiya above, I didn't realize it was capable of such close focusing (long draw). Makes sense now.

Like you I use a Yashicamat a 124, as well as 2 Rolleiflex cameras and a Microcord, We don't have these issues but I used to own a Mamiya C33 and C£ in the 70's early 80's until they were stolen but ideally you needed the Pramender, a device that sat on your tripod, you focussed close with the viewing lens then raised the body so the taking lens was in the position of the viewing lens. I never owned one but used the column on my tripod - I shot a large jewellery catalogue with my C33 this way.

Ian

Sudeep · Dec 19, 2018

MattKing said:
Four feet is 1200 mm.
That is 15 times the focal length of your lens.
You basically don't need to worry about exposure compensation until the distance from camera to subject is less than 8 times the focal length of the lens.
The lens-extension exposure dial in the Kodak Master Photoguide is your friend .

Thank you so much Matt! Really helpful info.

GRHazelton · Dec 19, 2018

Ian Grant said:
Like you I use a Yashicamat a 124, as well as 2 Rolleiflex cameras and a Microcord, We don't have these issues but I used to own a Mamiya C33 and C£ in the 70's early 80's until they were stolen but ideally you needed the Pramender, a device that sat on your tripod, you focussed close with the viewing lens then raised the body so the taking lens was in the position of the viewing lens. I never owned one but used the column on my tripod - I shot a large jewellery catalogue with my C33 this way.

Ian

Paramender.... Minolta made a similar device for the Autocord, an example of which I own. I'd like to find Minolta's version; it looks really easy to use. A discussion of the Mamiya TLRs mentions a lens to lens axis separation of 50mm, is this distance common to all TLRs?

Exposure Comp for TLR's?

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