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View Full Version : Wista 45DX focusing problem, astigmatism? Try a bright screen?



laphotographe
9-Apr-2012, 09:38
Shooting with 2 Wista 45DX field cameras (4 and 6 years old, new when purchase, original Wista fresnel screens)
Primary lens: Nikkor-W 135 mm f/5.6
Secondary lens: Nikkor-W 105 mm f/5/6
Loupe: Wista 5x standard loupe

I have been shooting with a pair of Wista 45DX cameras for about 6 years, and I’ve had a problem with focus fairly consistently throughout this time. I have been loosing more negatives than I should to bad focus. Typically the focus fall just in front of where I intended to put it. I primarily shoot portraits and end up with the person’s garment in focus instead of the eyes, for example. I tend to shoot at a distance of 3-10 feet from my subject. My solution has been to stop down as far as the lighting situation will permit (f/11-ish), throw a little fill strobe and hope for the best. I use a loupe and a proper dark cloth. Admittedly this method works, but not as well as I’d like.

Over the years I’ve had my eyes checked regularly and I wear appropriate glasses, yet the problem remains fairly constant. I have astigmatism in both eyes, and I wonder if this contributes to my problem focusing. I am only 33 and my eyes are not that bad, however.

I’m wondering if any of you have dealt with a similar problem, or if you have any suggestions to improve my focusing issue. I’m wondering if this is a problem with my cameras/lens/loupe, or my ability to focus. Would it be helpful to have a bright screen installed on my camera? Would a right-side up viewer be of any help (I am one of those photographers who has to turn her head upside down to compose the photograph)? Any thoughts would be much appreciated.

darr
9-Apr-2012, 09:52
I too wear glasses and have astigmatism in both eyes. The only time I know I have had problems with focus is when I have opted to wear my contact lenses instead of glasses. Shooting portraits with LF can be a challenge with limited depth of field and the inability to "live focus" with your subject. How is your focus results with still objects at the same overall settings?

Adrian Pybus
9-Apr-2012, 10:14
And do you focus using the same fstop that you will expose with?

Brian C. Miller
9-Apr-2012, 10:16
I have been loosing more negatives than I should to bad focus. Typically the focus fall just in front of where I intended to put it.

Your eyes may be good enough, but your ground glass position may have a problem. Do you have a loupe you can use on your ground glass? Try this test: Get some box cardboard, and cut it into strips to make a series of steps. Glue a piece of newspaper on each step. Using the loupe, focus on the middle step, making sure you can read the print. Now make a normal exposure, develop the film, and see if the middle step is in focus. If it isn't in focus, then your ground glass is out of alignment with the film plane.

When I bought my Super Graphic, the ground glass had been replaced with normal ground glass instead of the original glass and Fresnel combination. I bought a Brightscreen replacement, and after futzing around, shimmed it into place with a strip of sheet film negative and a strip of 35mm negative. (Previous thread: Registration (http://www.largeformatphotography.info/forum/showthread.php?6952-Registration&p=47177))

If you don't want to get artsy-craftsy like I did, then send your camera to a repair tech for adjustment.

Vaughn
9-Apr-2012, 10:17
I suggest photographing (wide open) a newspaper taped to a wall at your normal working distance and see how your focus is on the neg. The other way is to focus on a ruler (say at the 6" mark) and see where the actual focus is on the negative. Nail down the exact problem.

If your focus is fine in the above circumstances, then perhaps your subject moves a little away from the camera after you focus.

If your focus is off, then perhaps, even tho the cameras were new, the film is not ending up on the exact plane as the GG.

Bob Salomon
9-Apr-2012, 11:18
Have you adjusted the loupe to be in focus on the grain side of your ground glass? That should be step #1 for all cameras.

laphotographe
11-Apr-2012, 08:35
Thanks to everyone for your thoughts.

I ran some tests based on Brian's and Vaughn's suggestions and I should have the film back in the next few days.

Bob, I'd like to ask you to clarify your question regarding focusing the loupe on the grain side of the ground glass. My loupe is adjustable, but I thought that it should only be adjusted like a diopter based on eyesight. Given that I wear glasses, I didn't think I needed to adjust the loupe, but perhaps I am wrong about this? How would I focus on the grain side of the ground glass?

Adrian, I focus wide open.

Darr, I'm glad to hear that I'm not the only one who cannot focus with my contacts in. I just did a test to see if my focus is good with still objects as I'm honestly not sure.

E. von Hoegh
11-Apr-2012, 08:49
Focus the loupe so you can see the texture of the groundglass clearly and in focus. You mentioned that you have astigmatism, but not if you are near or far sighted. If you focus the loupe without your glasses, be sure to use it with your glasses off. If you focus the loupe with, use it with the glasses. Personally, I find Fresnel an annoyance and never use it.

Doremus Scudder
11-Apr-2012, 09:23
Do check the position of your ground glass. I had some problems with my Wista DX after installing a factory Fresnel screen. Also make sure that the screen is seated properly.

And, yes, it is a good idea to make sure you loupe focuses correctly, but, even if it is off a little, it shouldn't make any difference to the focus, just the sharpness of the image you actually view.

I'll wager there is a misalignment somewhere.

Best,

Doremus

Bob Salomon
11-Apr-2012, 09:36
To adjust the focus of your loupe properly. Turn on a light in front of the camera, remove the lens. Focus your loupe on the ground glass until the grain of the gg is in sharp focus. Now put your lens back on and shoot.

Assuming that you have a Wista gg and a Wista fresnel installed on your camera and assuming that you had not focused your loupe then when you placed your loupe on the fresnel and focused you were out of focus by the thickness of the fresnel + the thickness of the gg + any space between the 2.

If you don't have the fresnel then you would have been out of focus by the thickness of the gg.

In photographic terms those can be large errors in focus.

laphotographe
11-Apr-2012, 11:49
To adjust the focus of your loupe properly. Turn on a light in front of the camera, remove the lens. Focus your loupe on the ground glass until the grain of the gg is in sharp focus. Now put your lens back on and shoot.

Assuming that you have a Wista gg and a Wista fresnel installed on your camera and assuming that you had not focused your loupe then when you placed your loupe on the fresnel and focused you were out of focus by the thickness of the fresnel + the thickness of the gg + any space between the 2.

If you don't have the fresnel then you would have been out of focus by the thickness of the gg.

In photographic terms those can be large errors in focus.

Great, this is helpful. When I adjust my loupe I can focus either on a sand pattern (which I assume is the grain of the glass?) or on a series of concentric thin black lines (the fresnel?). I should focus on the sand pattern, right?

E. von Hoegh
11-Apr-2012, 11:51
Great, this is helpful. When I adjust my loupe I can focus either on a sand pattern (which I assume is the grain of the glass?) or on a series of concentric thin black lines (the fresnel?). I should focus on the sand pattern, right?

Correct.

Bob Salomon
11-Apr-2012, 12:38
The grain pattern.

grinalip
11-Jul-2012, 22:26
Re: Wista 45DX focusing problem, astigmatism? Try a bright screen? (http://www.squidoo.com/sony-rx100)

I ran some tests based on Brian's and Vaughn's suggestions and I should have the film back in the next few days.

any results yet? I too have astigmatism and would like to hear how you were able to solve the problem

laphotographe
12-Jul-2012, 15:17
any results yet? I too have astigmatism and would like to hear how you were able to solve the problem

So far the issue is only partially solved. I did adjust my loupe as per Bob's suggestion, and that was helpful. The focus tests also seemed to come back ok. However, I am still loosing more images that I would care to loose when I make portraits. The problem is not systematic, so I am having some help tracking it down. For what it is worth, I am being careful to focus with my head right side up (not upside down, as I often compose my photographs) so that my eyeglasses are definitely in the correct position for my eyes when focusing. Grinalip, have you found anything else that helped?

Bob Salomon
12-Jul-2012, 16:18
So far the issue is only partially solved. I did adjust my loupe as per Bob's suggestion, and that was helpful. The focus tests also seemed to come back ok. However, I am still loosing more images that I would care to loose when I make portraits. The problem is not systematic, so I am having some help tracking it down. For what it is worth, I am being careful to focus with my head right side up (not upside down, as I often compose my photographs) so that my eyeglasses are definitely in the correct position for my eyes when focusing. Grinalip, have you found anything else that helped?

What are you focusing on when you take a portrait? What focal length lens? What f stop? What do you mean by a portrait? Head and Shoulders? 3/4? environmental? etc.

laphotographe
13-Jul-2012, 10:02
What are you focusing on when you take a portrait? What focal length lens? What f stop? What do you mean by a portrait? Head and Shoulders? 3/4? environmental? etc.

Hi Bob, thanks, I am working with a 135mm lens, generally stopped down between f8 and f16. I shoot at a variety of distances, and what I've noticed is that the closer photographs (head and shoulders) tend to be very crisp, but those a bit farther away (full body / environmental) are where the focus tends to be a little bit off. I focus on the eyeballs.

Bob Salomon
13-Jul-2012, 12:15
What lens? 135mm is too short for a head and shoulders shooting full frame 45. You will have fore shortening exagerate noses, chins, foreheads, etc.

Keith Fleming
13-Jul-2012, 21:14
I found that for me the easiest way to adjust my loupe was to just take a pencil and write an "X" in the middle of the frosted side of the ground glass. This gives a target that makes for easy focusing of the loupe. I can use that X to quickly double-check the loupe in the field. Also, I use gaffer's tape to keep my loup properly focused--and, yes, the tape has left hard residue on the loupe after being there for a few years.

Keith

laphotographe
16-Jul-2012, 13:45
The lens is a Nikkor-W 135mm f/5.6, about 7 years old. I have found it to be very appropriate for portraits.


What lens? 135mm is too short for a head and shoulders shooting full frame 45. You will have fore shortening exagerate noses, chins, foreheads, etc.