DaYi 6x17 - how to mount a lens and calibrate it?

[Jeff Bannow]

So, I'm trying to align and calibrate both a 90mm and 210mm lens onto a DaYi Shift IIA 6x17 camera.

Here's the camera:
http://bhcamera.us/dayi617.php

I can get the lens mounted (that part is easy - just like on 4x5), and can see an image in the ground glass, but can't seem to get it in focus at infinity. Anyone have one of these and know the trick?

 

[Paul Sorensen]

Okay, I don't know anything about this camera, but I am going to throw this out there since no one has replied to you yet. The ad you linked to indicates that it comes with an adapter for a 75mm lens and that other adapters are additional. Do you have the adapters for the 90mm and 210mm lenses? I am guessing that the adapter is necessary to bring the lens far enough away from the film plane to focus.

If that is not it, than I have no idea.

 

[Jeff Bannow]

I do have the right length cones for it, fortunately.

 

[Paul Sorensen]

Well, good luck then!

 

[JLP]

Hi Jeff,
I do have the exact same camera so here goes.
Right in front of the cone there is a plain ring just behind the fine saw tooth ring, this ring has a couple of small screws. You loosen these and then turn the whole front CCW until you start to get your image in focus.
I measuered an object about 5 meter from the lens, set the focus ring to 5m and then adjusted the whole front assembly til it was in focus. Then turned back the saw tooth ring to be snug with the cone and tightened then two small screws again.

It does take a few tries and you will eventually have to rotate your lens so you can see your aperture and shutter settings but once done it works pretty well.
Please let me know if you need more details or if i forgot to mention something.

 

[Jeff Bannow]

So, we took another stab at it today. Working with the 90mm Fuji f8, we removed the lens from the cone and started over. Made sure the lens was mounted firmly and properly.

Then, we loosened the large helical retaining ring and completely unscrewed the helical focusing thingie. We then screwed the helical back in the minimum that is needed to keep it attached. This still wasn't far enough out - I had to focus the helical to 3 meters in order to get enough distance to get it focused at infinity.

Now, this lens is listed on the compatibility chart. It should work.

Is there another adjustment I'm missing to move everything out another 1/4" or so?

I attached a photo of the camera as configured to focus at infinity.

 

[Jeff Bannow]

Ian C tipped me off to the idea of the flange to focal distance might be the problem. Seems that this is the issue.

For fun, I tried mounting an Angulon 90mm f6.8. This didn't work, but because I couldn't get it close enough to the film plane. (it also wouldn't cover, but that's a different issue)

So, I may need to buy a new lens! Sigh.

 

[Jeff Bannow]

Please let me know if you need more details or if i forgot to mention something.

Which 90mm lens are you using with yours?

Thanks.

 

[JLP]

I am using the Nikon 90mm f4.5
With this lens the helical ring is all the way out and only attached with a couple of threads.
Hope you can get it to work.

 

[LJH]

This, I hope, is a stupid question: Have you made sure that you've removed the pointless little screws on the back of the shutter?

 

[Ian Grant]

There's a file online somewhere telling you how to adjust the lens helical, I did save it I'll try and find it & email it. There's two small screws inside the helical mount that need adjusting.

The camera's actually made by Gaoersi so the lens helical is the same. When I bought mine the helicals were set specifically for the two lenses before shipping. It's a bit fiddly that's why the chines seller wanted to know exactly what lenses, there was a difference between my 90mm SA & Grandagon, so I had to chose which to use,

File's already sent

Ian

 

[Jeff Bannow]

I did indeed. It looks like it is a flange to focal distance issue.

Got the file - thanks Ian!

 

[Jeff Bannow]

Looks like I got it worked out - here's the first roll ....

 

[michael9793]

The site you refer to at the bottom has instructions on how to mount the lens and register it at infinity. Also LJH does have a point make sure that stupid screw is removed and the lens is flush.

 

[LJH]

Looks like I got it worked out - here's the first roll ....

What was the problem in the end, Jeff?

 

[Jeff Bannow]

What was the problem in the end, Jeff?

It was the flange to focal distance for the lens I was trying - it was beyond the range of the lens cone. I had to buy a different 90mm lens that fit to the cone.