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02-17-2012, 12:23 PM   #1
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Modifying the DA40 to use on MX

I understand that the DA40 and all other modern lenses without aperture rings will stop down fully on older film camera's that can't control aperture through the body. I was wondering if there was any way to physically modify the lens to shoot wide open all the time? (or even better, stopped down a bit)? I'm looking to shoot with an MX+DA40, which would be a great pocketable combination, even if I could only shoot at f2.8. Has anyone done anything like this?

02-17-2012, 12:31 PM   #2
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QuoteOriginally posted by ironlionzion Quote
I understand that the DA40 and all other modern lenses without aperture rings will stop down fully on older film camera's that can't control aperture through the body. I was wondering if there was any way to physically modify the lens to shoot wide open all the time? (or even better, stopped down a bit)? I'm looking to shoot with an MX+DA40, which would be a great pocketable combination, even if I could only shoot at f2.8. Has anyone done anything like this?
I think a few forum members have tried DA lenses on film and they will work with some vignetting?

I would get the FA43/1.9 as it is designed for film and a faster lens.

Phil.
02-17-2012, 12:36 PM   #3
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or you could get the M series 40mm 2.8. not a whole lot of difference between the two. though I'm not sure how they compare optically. the MX was originally advertised with the M series 40mm pancake for the very same reasons you want to use the DA.
02-17-2012, 01:01 PM   #4
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Agree with seamuis, grab an M 40mm for cheap, would be better than hacking your DA 40

02-17-2012, 01:06 PM   #5
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Alternately, get a Program Pentax, they work fine with the DA40, and are cheaper than the new lens direction.
I started to write something about tape being your friend, but realize the camera and lens do talk to each other. But correct me if I'm wrong, when mounted, the DA40 will ALWAYS be fully open? So you can shoot that way (I've done so with my DA70).
02-17-2012, 01:10 PM   #6
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QuoteOriginally posted by Nesster Quote
But correct me if I'm wrong, when mounted, the DA40 will ALWAYS be fully open?
this is correct.you won't have the ability to stop down at all without modification. mounting the lens will open it to max aperture.
02-17-2012, 01:43 PM   #7
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I've searched this topic, and apparently DA lenses fully stop down on older cameras. I read the thread on these forums last night but now I can't seem to find it....
02-17-2012, 01:46 PM   #8
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"Now the big one on the MX:
The lens will always shoot at minimum aperture
Yep, that is an inconvenient truth. The MX is unable to control the aperture from the body which results in the following fatal condition...metering is done wide open, but shooting is done fully closed. You might be able to fool the meter by using the DOF preview to get a stop-down meter reading.

Sorry

Best to stick with lenses that have aperture rings with the MX.

Steve"

https://www.pentaxforums.com/forums/pentax-film-slr-discussion/80893-what-hap...rogram-mx.html

02-17-2012, 01:55 PM   #9
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But yeah, I think the m40 or Program plus would be a better direction....off to ebay!
02-17-2012, 01:58 PM   #10
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I just tried it and you are right. Ive never used a DA lens on any film body before, but I just tested the DA* 55 and yup. meters wide open and shoots closed down. so, ill reiterate my first statement. if you really want a pocketable camera, you could go with the M 40 instead of the DA. the same benefits (again, I don't know how they compare optically) but you retain full control of the aperture. also a better dampened focus ring, if that makes a difference.
02-17-2012, 02:09 PM   #11
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Hey, I learned something new today! I guess I've only used the DA70 on a Pgm Plus or a XZ autofocus thingie.
02-17-2012, 03:07 PM   #12
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QuoteOriginally posted by ironlionzion Quote
But yeah, I think the m40 or Program plus would be a better direction....off to ebay!
Unfortunately it looks like the optics on the M40 are less than stellar and it is expensive for what you get.

SMC Pentax-M 40mm F2.8 Reviews - M Prime Lenses - Pentax Lens Reviews & Lens Database

The FA43 on the other hand are superb.

Phil.
02-17-2012, 03:38 PM   #13
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Yeah I just looked up test photos here of the DA40 vs M40....http://dc.watch.impress.co.jp/cda/review/2005/01/17/753.html

The DA is sharp wide open, but stopped down one and the M40 catches up. The worst part of the M40 is that the bokeh is terrible with the 5 blade aperture rings. The pentagons aren't the prettiest thing to see....but either way I bought a M40 from a member here...I'll see how it works out. One day I'll get a FA43...one day....
02-17-2012, 05:33 PM   #14
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QuoteOriginally posted by gofour3 Quote
Unfortunately it looks like the optics on the M40 are less than stellar and it is expensive for what you get.

SMC Pentax-M 40mm F2.8 Reviews - M Prime Lenses - Pentax Lens Reviews & Lens Database

The FA43 on the other hand are superb.

Phil.
according to the photos in the link above, id say the M performs very well. probably not as sharp wide open, but I don't think its optically inferior. its only weakness seems to be the shape of the aperture in concern to the OOF highlights.
02-17-2012, 05:44 PM   #15
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QuoteOriginally posted by séamuis Quote
according to the photos in the link above, id say the M performs very well. probably not as sharp wide open, but I don't think its optically inferior. its only weakness seems to be the shape of the aperture in concern to the OOF highlights.
Yeah it's not a terrible lens by any means; it would mostly depend on the price. I was looking for one a year ago and the prices were very high for what you are getting. You can get a K35/3.5 for less and that lens is not much bigger and has superb optics. But if you are looking for small/pancake you only really have a couple options.

Phil.
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