5x4 lens help, have i wasted money

[AshleyC]

ok ive got my Wista 5x4 and it came with a 150mm lens which is fine. I wanted something wide so got a 90mm Schneider Super Anguon 5.6 and it came today. However, focusing seems odd.

I can point it at the telly which is about 8 feet away and i can get it into focus by pulling the lens/bellows right back towards the glass plate which just doesn't seem right? plus there seems to be a load of vignetteing

However roughly measuring the distance between glass and lens does give me around 90mm. Is 90mm just too wide for the body? ive seen some lens plates that are recessed so maybe getting one of them to keep the lens further from the glass would help?

Just a bit confused with it. Maybe its find and will be ok in print. I think its the apparent vingette that is confusing me coupled with having to drag it back so close to the glass. Maybe everything is just ok and thats how it works?

 

[raathistle]

With a 90 focussed at infinty it is surprisingly close to the ground glass, but focussing at 8 feet it should be a bit further away. I'm guessing its the 90mm 5.6 MC, not the XL, which is the same as mine and you will likely see a huge vignette if you don't have a fresnel fitted. Even with one it still has some vignetting simply because the big rear element is pretty close to the GG, but it will be better

To check your coverage you can look through the clipped corners and if you can see the whole aperture hole it won't be a complete vignette. The fall off on 5x4 is actually pretty good and I don't see the need for a centre filter personally

 

[Nguss]

Wide angle lenses on some cameras require bag bellows as there is not much room for focussing when the lens if brought so far back so that sounds right to me. I am not sure about the Wista, so you may want to look into that or recessed lens panels as an alternative.

The image circle on the 5.6 seems the same as my super angulon 90 f8 so it should cover the 4x5 frame at f22.

http://www.schneideroptics.com/info...ormat_lenses/super-angulon/data/5.6-90mm.html

Forgot to add that I dont see the need for a centre filter at 90mm either.

 

[AshleyC]

thanks peeps. I think the ground glass is confusing me. Unless you look directly at it you dont get a bright image, keeping your face central and just looking into the corners gives the shadows, moving my head around the glass while keeping 90 degrees at it gives me a clear image. Hopefully will finally get a dry weekend this weekend to get out and use it to find out for sure!

I cant say exactly how far its off the glass as i cant get my ruler close enough for an accurate read but its in the ballpark.

Why is f22 a crucial figure? does the image shrink and enlarge the wider/smaller you go? and whats a centre filter?

 

[Steve Smith]

I cant say exactly how far its off the glass as i cant get my ruler close enough for an accurate read but its in the ballpark.

If you have a spare lens board without a lens fitted, you can focus with the lens then swap it for the empty board and use a ruler through the hole to measure from the ground glass to the front of the lens board.

This is what is referred to as the 'Flange Focal Distance' in the Schneider data sheets (film to back of the shutter distance).

If you think you have problems with a 90mm, I'm trying to design my next 5x4 camera to take a 65mm Super Angulon.


Steve.

 

[Nguss]

I dont mean to ask a daft question but have you used a wide angle lens on 4x5 before as the wider the lens generally the darker the image on the ground glass, so what might look like vingetteing may not be in reality.

I am not sure why image circles are measured at f22.

Light tends to drop off at the ends of wide angle lenses and a centre filter corrects this but they are expensive and I have never needed one at 90mm using colour film.

Finally your lens is not a waste of money, I would have gone for that myself if the 90mm f8 was not cheaper.

 

[AshleyC]

never used a 5x4 before lots of medium format but that's just a normal camera, just bigger!

I just wasn't sure about what lenses work with the body, the light bub above head moment was just realising the 90mm focal range means the distance between lens and film so it would be quite scrunched up on this body. Sticking the 150 on and, hey presto, thats roughly 150mm away from the glass as well when its focused. Panic over

 

[Nguss]

Yup it is a steep learning curve but the results are definitely worth it. You may also want to consider a 210mm as well eventually, I have one and find it a joy to use.

I need to get out and shoot more film as I have got lazy and started using digital a lot. I look forward to seeing the results of your foray into 4x5!