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03-06-2014, 07:12 PM   #31
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d-mount adapters

Hello all. My first post here, glad to join the forum!
A quick question. I have 4 d mount lenses that I am using on my Q. Only one has a focusing ring, so focusing with the other 3 is an issue. Actually, for all 3 of them I have to unscrew them a little from the adapter in order to be able to focus (some times more than halfway). I am using a cheap ($5) adapter that I got from ebay. I noticed that there is also a kipon adapter ($40 - $50) available. Anyone has experience using this one? Or, even better, both? I am wondering if it can make a difference, in relation to the focusing problem.
Thanks!

03-06-2014, 08:41 PM - 1 Like   #32
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QuoteOriginally posted by rafoarc Quote
Hello all. My first post here, glad to join the forum!
A quick question. I have 4 d mount lenses that I am using on my Q. Only one has a focusing ring, so focusing with the other 3 is an issue. Actually, for all 3 of them I have to unscrew them a little from the adapter in order to be able to focus (some times more than halfway). I am using a cheap ($5) adapter that I got from ebay. I noticed that there is also a kipon adapter ($40 - $50) available. Anyone has experience using this one? Or, even better, both? I am wondering if it can make a difference, in relation to the focusing problem.
Thanks!
i had the same issue with a couple of my d mount pan focus lenses. Through another PF member, I learned that McMaster Carr sells ultra thin brass shims that you can put between the lens and adapter to correct your focus. [url=http://www.mcmaster.com/#brass-shims/=qzfla0]McMaster-Carr[/url

here's the thread about the shims https://www.pentaxforums.com/forums/136-pentax-q/240506-c-mount-lens-shims.html

i believe I ordered 5/8" ID shims for my D Mounts

Last edited by emergo; 03-06-2014 at 08:50 PM.
03-06-2014, 10:05 PM - 1 Like   #33
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Welcome to the Q and forum, rafoarc. The Q allows the use of many exciting lenses outside the system. You are navigating one of those paths with D mount lenses. What other ILC even allows this?

Think emergo has the best plan for dealing with focus errors. Some of the error seems to be due to the adapter and some to the individual lens. I would dedicate one adapter to each lens. Shim each lens once and leave it. I have tried C but no D mount yet. Will remedy that some day.

thanks
barondla
03-06-2014, 11:19 PM   #34
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Thank you guys. The 'shiming' method looks like something that is going to help! will try that soon!

04-05-2014, 08:42 AM   #35
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QuoteOriginally posted by Shawn67 Quote
" but nothing as wide as a 4, and certainly not for C Mount"

They are out there. I have a 2.5mm C mount fisheye for example. Pentax/Cosmicar has a 4.8mm C mount lens that is a nice focal length on the Q. I have a 3.6mm (I think) but it optically isn't as good as the 4.8.

Shawn
there are some new 4.8 Pentax C Mount lenses on ebay right now

Pentax C30405TH 4 8mm F1 8 C Mount CCTV Lens Brand New Free Shipping | eBay

or a lot of 4 used ones for the same price as one new

http://www.ebay.com/itm/PENTAX-C30405TH-4-8MM-1-1-8-C-MOUNT-CCTV-LENS-LOT-OF...item417dfdb783

erik

Last edited by emergo; 04-06-2014 at 06:04 PM.
04-06-2014, 11:05 AM - 1 Like   #36
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Tested 10 D-mount and C-mount lenses today

First of all, the adapters. I buy the cheapest adapters from China, $6 and free shipping. I brush off the cheap black paint on front and sides, and polish them to a high shine to mach the beautiful lenses from the 50's and 60's. I use shims of brass, black plastic, black paper, and ultra thin rice paper. By varying the tightening I get into around 1/100mm in accuracy. Once a lens is perfectly calibrated at infinity and 30cm it stays on the adapter. 1 adapter per lens. I the loosen the set screws on the lens and rotate them so that markings are on the top. From start to finish I spend about 1-2 hours per lens. Now, this is just the setup. I think it is vital for street photography to have everything lined up right.
The test today was of lenses from Kern Paillard, more specific, the designs from Hans Schlumpf, and 2 Cosmicar lenses, and the 01 8,5mm Pentax Standard Prime as reference.
I will not post test images because of the limits in this forum, but rather give a description of my findings.
My test subject matter was a dummy my daughter made in a garden chair. I wanted a "real life" scenario to test DOF and center resolution. Almost all these lenses are made for a 3,5x4,5mm frame, while the Q7 that I used is almost twice that.
Findings:
Only 2 lenses showed vignetting from wide open, the IDEAL Hannover 6mm f.1.9, and the Switar 5,5mm f.1.8. I use them for square 1:1 imagery. When masked down and sized up to the Standard Prime (SP) 8,5mm, the IDEAL Hannover fell through in both resolution and contrast. The Switar 5,5mm was on par with the SP regarding resolution, but had better contrast and clearer colors and less bleeding into darks. The Pentax SP turned out to be a big disappointment compared with these tiny glass and metal lenses. Compared with the Kern Yvar 12,5mm f.2.5, the Kern Switar 13mm f.0.9 it is no good, even when distance was adjusted to match the field of view. The Yvar 13mm f.1.9 is not a good lens either, but a triplet design should never be made with a large aperture. It suffers on all apertures for this and is not recommended for other than "toy-like" effects. The Yvar 12,5mm f.2.5 is a fix focus design, and I have calibrated mine at 10meter. At f.4.0 it is sharper and more contrasty then anything I have seen. This was one of the three biggest surprises in my little test. The second was that the Pentax SP was so bad in comparison. The Switar 13mm f.09 isa fantastic lens in its own way. Only flaw is that it starts to vignette at f.2.0, (but then one can switch to the Yvar 12,5mm). A larger version (18mm f.0.9 for C-mount) was ordered by NASA for the Apollo 11 moon landing. The lens is super sharp in center at f.0.9, but low in contrast. At f.1.4 it is stellar, and covers the full frame of the Q7 with beautiful bokeh. The third surprise was the Yvar 36mm f.2.8. Even though it's just a triplet, the center piece of glass is so perfected by Hans Schlumpf that it has no CA what so ever. H.S. calculated the thickness and curves of the glass in order to have this exact effect. In resolution it is also better than its 8-element larger Switar 36mm f.1.8 brother. The only advantage the Switar has is the 1 and 1/3 larger aperture. To conclude: Yvar 12,5mm for landscape at f.4.0 to f.5.6, Yvar 36mm f.2.5 at 4.0 to 5.6 for landscape, the Switars 5,5mm, 13mm and 36mm for street and portraits, very good at all apertures up to f.5.6. Resolution takes a big hit on all lenses at f.8.0, but bokeh at edges are nicer.
The 2 Cosmicar lenses ar up for sale in a while. The 25mm f.1.4 is nice, but nothing near the Kern Paillard Yvar and Switar. The 6mm f.1.2 is a big CA joke, only suitable for experienced BW photographers as an alibi for making art
Here is a picture with Switar 13mm f.0.9 at f.0.9 of the dummy my daughter made for me. Full frame, no crop, on Q7. It has a certain amount of character, but it is super sharp in the center. It does not show here in the down-scaling, but it really is.
Oh, by the way, I tested the Kern Paillard because the were the best in the world at the time, and because I have become a huge fan of the mathematic genius of Hans Schlumpf. These lenses (the ones after 1955-56) are computer designed. Kern started to use computers at that time to test out theoretic design possibilities. The even had coating on their lenses as early as 1942. Ok. I'm a nerd. But it's very exiting
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04-22-2014, 10:24 PM   #37
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Here's some shots taken during the holy week events here in my place, with the Canon 8-48mm f/1.0-1.2 C-mount, a lot of the shots here were taken in Macro mode (at 8mm) f/1.0-2.8. The wide shots were at 8mm and had MASSIVE CA, but that can be used positively (great for artful shots). I enjoy shooting with this lens, now I want to go out and buy more C-mounts to try on my Q!
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07-05-2014, 03:25 PM   #38
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Hi chaps
i just scored a free Kern Paillard Yvar 12.5/2.8 fixed focus off a bolex 8mm.
My D-P/Q adapter seems to be the wrong registration distance ( the adapter is about 4mm proud of the mount)
It only focusses about 1 inch out
any clues appreciated

07-05-2014, 03:53 PM   #39
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Hi,
Please read my post above. Make shims out of black paper, plastic or whatever material you have. I find a curved pair of scissors for nails ideal for this use. I focus this lens at about 10 meters. At f.5,6 everything from 1 meter to infinity is sharp. Fantastic lens for landscapes and way better than anything Pentax regarding color, CA, sharpness and contrast. The best lens for Q by a huge margin. Good luck.
07-05-2014, 05:08 PM   #40
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Hi!
Transit, what do you mean "It only focusses about 1 inch out"? It focuses at objects that are at 1 inch distance from the lens??
07-05-2014, 09:46 PM   #41
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QuoteOriginally posted by NoRules Quote
Hi,
Please read my post above. Make shims out of black paper, plastic or whatever material you have. I find a curved pair of scissors for nails ideal for this use. I focus this lens at about 10 meters. At f.5,6 everything from 1 meter to infinity is sharp. Fantastic lens for landscapes and way better than anything Pentax regarding color, CA, sharpness and contrast. The best lens for Q by a huge margin. Good luck.
Good news thanks
will get onto it.
Weird that mine is a 2.8, you and the K-P wiki had it at 2.5
maybe mine is one of three made and I can now clear my mortgage


---------- Post added 07-06-14 at 04:48 PM ----------

QuoteOriginally posted by rafoarc Quote
Hi!
Transit, what do you mean "It only focusses about 1 inch out"? It focuses at objects that are at 1 inch distance from the lens??
yes what did I mean
out to an inch was what I was attempting to articulate.
Tried slowly unscrewing it but not sure it helped

Last edited by Transit; 07-05-2014 at 09:57 PM.
07-06-2014, 02:06 AM   #42
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ok, so if you are able to focus at objects 1 inch from your lens, unscrewing will not help, you need the opposite. I had a similar problem with a walz 38mm f1.4. It turned out that there was some kind of extension tube screwed in the back of the lens, turning it into a macro. I just had to take that out. Stupid, put it took me some time to figure it out. Is it possible that something like that might be your problem?
07-06-2014, 02:32 AM   #43
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rafoarc I think you are right it needs to mount further in not out.
no sign of any tubes on the back sadly
07-06-2014, 05:12 AM   #44
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QuoteOriginally posted by Transit Quote
rafoarc I think you are right it needs to mount further in not out.
no sign of any tubes on the back sadly
As stated in my original post on the Kern Paillard subject, I always sand my adapters down 1 mm, then I add shims as needed. Adapters are of soft aluminium alloy or something. Very easy to sand. Stay with it! Don't give up!
07-06-2014, 06:10 AM   #45
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the thing is, if it focuses at 1 inch now, then it needs to get quite a lot closer, I am not sure if 1mm will help, but then you never know. but i think that there might be some other issue there... can you post a photo of the back of the lens and of the lens on the adapter?
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