Aero Ektar focussing tips

[Andrew Sillett]

Hi everyone,

I knew that focussing an Aero Ektar on a Speed Graphic was going to be difficult wide open (f2.5) but after shooting 12 frames now, the last 4 with a loupe, I have yet to nail focus on the eyes.

I have shot at various distances, ranging from about 3m to 1m. I use a focussing cloth hood.

I cleaned my ground glass and fresnel too.

Any tips, other than stopping down the lens? I don't know what else I can do.

Best,
Andy

 

[gone]

You may have to stop it down a wee bit more. This is becoming something I have to watch out for on a first version Leicaflex 90 2.8 Elmarit that I bought specifically for portraits and close up work. The depth of field when wide open, especially close up, is much more shallow than I'd expected at 2.8, and so it ends up being stopped down just a little. Can't see any change in bokeh, but it sharpen things up a bit.

A 7" 2.5 lens on what I assume is a 4x5 version of your camera has a ridiculously small margin of error. Try some shots taken in series, and stop it down a little each shot. The prints will tell you the sweet spot.

 

[outwest]

I put a nice one on a Speed Graphic and tried it out. Then I gave the lens away.

 

[Andrew Sillett]

You may have to stop it down a wee bit more. This is becoming something I have to watch out for on a first version Leicaflex 90 2.8 Elmarit that I bought specifically for portraits and close up work. The depth of field when wide open, especially close up, is much more shallow than I'd expected at 2.8, and so it ends up being stopped down just a little. Can't see any change in bokeh, but it sharpen things up a bit.

A 7" 2.5 lens on what I assume is a 4x5 version of your camera has a ridiculously small margin of error. Try some shots taken in series, and stop it down a little each shot. The prints will tell you the sweet spot.

Yes, that sounds logical. I will try it out and report back.

 

[Andrew Sillett]

I put a nice one on a Speed Graphic and tried it out. Then I gave the lens away.

I am trying to avoid that outcome. I have seen some nice work with the lens, but am nowhere near that yet.

 

[abruzzi]

I'm wondering, with an ultra shallow depth of field, between focusing and inserting the film, removing the darkslide, etc., is your subject moving enough to kill the focus?

 

[grain elevator]

I'm wondering, with an ultra shallow depth of field, between focusing and inserting the film, removing the darkslide, etc., is your subject moving enough to kill the focus?

And is the film flat enough?

 

[Bronson Dugnutt]

Just for reference, you're working with 14mm and 144mm of DoF with that setup at 1 and 3 meters, respectively. Equivalent to a 47mm f/0.7 on 35mm. I'd recommend stopping down a bit if critical sharpness is your goal. You won't be wanting for bokeies if you can control the distance between your subject and the background. Softness wide open at close distances isn't unexpected given Aero lenses were designed to be used at infinity.

Handy DoF tool:
https://www.pointsinfocus.com/tools/depth-of-field-and-equivalent-lens-calculator

Edit: These thingies are nice for auto-focus testing, but also useful for gauging lens calibration at close distances.

 

[ic-racer]

Stopping down won't change your focal point if you focus at taking aperture.
Make sure your loupe focuses on the ground glass corectly.
Use a stationary object for testing. If the negative shows the focal point behind where you focused, your ground glass is too far back from the lens..
If the negative shows a focal point in front of where you focused, your ground glass is too close to the lens.

 

[Andrew Sillett]

Guys, thank you for you suggestions.

With a human subject, I can't definitively say that they didn't move (despite urgent commands to stay still), so I will now use a stationary object to test focus.

Inserting the film holder could upset the focus, I guess.

I stopped down to f4 but the problem persists.

I think the negative shows the focal point behind where I focused (see pic)

If this my my ground glass is too far back from the lens, how do I correct this? I did take it out to clean it, so perhaps this affected it.

 

[Nicholas Lindan]

If all your shots show the same 5" (?) at the same shooting distance then I'd wager the problem is ground glass placement. If the point of sharp focus relative to where you focused varies from shot to shot then it could be movement. Inserting the film holder into a well screwed down Speed shouldn't move anything much at all.

 

[Andrew Sillett]

I took out the fresnel, but now the GG is slightly loose. I can insert a little card to push it slightly forward. Worth doing a test shot like this?

 

[Nicholas Lindan]

I took out the fresnel, but now the GG is slightly loose. I can insert a little card to push it slightly forward. Worth doing a test shot like this?

I would say no.

The cameras were available with and without the fresnel. The no fresnel models had little bosses for spacing the ground glass backwards by the fresnel thickness to make up for the lack.

Just as a sanity check, if your camera came with the factory fresnel - is the fresnel on the lens side of the ground glass, with (as rumour has it) the fresnel ridges towards the ground glass?

If yours is a no-fresnel model and someone put an aftermarket fresnel in on the lens-side then it may cause the problem you are seeing. In this case try moving the fresnel to the outside of the glass.

 

[abruzzi]

If yours is a no-fresnel model and someone put an aftermarket fresnel in on the lens-side then it may cause the problem you are seeing. In this case try moving the fresnel to the outside of the glass.

This is an interesting point. I've never used a fresnel on my LF cameras as I don't really like them, but as Nicholas says, some cameras were designed to have the fresnel between the glass and lens, and some were desinged to have the fresnel on the outside. It is critical for focus to be correct. I don't know the graphics at all, but with my Linhofs's I can take the entire back off, place a straight edge across the inside of the back, and use calipers to measure the distance from the glass tothe straight edge, then insert a film holder and take the same measurement. If the glass is too far back I don't know how to fix that, but if it is too far forward, you can make shims to push it back.

 

[Bob S]

This is an interesting point. I've never used a fresnel on my LF cameras as I don't really like them, but as Nicholas says, some cameras were designed to have the fresnel between the glass and lens, and some were desinged to have the fresnel on the outside. It is critical for focus to be correct. I don't know the graphics at all, but with my Linhofs's I can take the entire back off, place a straight edge across the inside of the back, and use calipers to measure the distance from the glass tothe straight edge, then insert a film holder and take the same measurement. If the glass is too far back I don't know how to fix that, but if it is too far forward, you can make shims to push it back.

Your LInhof gg rests on adjustable shims. 4 of them. Those are the silver rectangles that are on the very small screws. If your camera doesn’t have them then you need to talk to LInhof service centers.

 

[gordrob]

I found that with the ultra shadow depth of field at close distances that you have to have a very sturdy tripod and the camera has to be tightly secured to it to avoid any movement when the film holder is inserted. That caused me a lot of problem until I figured out what the problem was and changed my smaller tripod to a bigger Gitzo.
I am attaching a link to a very interesting series of articles on refurbishing a Speed Graphic to accommodate the Aero Ektar. There is a lot of interesting information as too tuning up your focal plane shutter and focusing methods.

https://emulsive.org/articles/build...ct-part-1-introduction-and-required-materials

 

[Andrew Sillett]

Removing the fresnel and shimming the GG (I had to look up what that verb meant) did the trick. In focus at f2.5 and even deeper at f4.

Thank you very much for all your help. Really appreciated.

 

[abruzzi]

Your LInhof gg rests on adjustable shims. 4 of them. Those are the silver rectangles that are on the very small screws. If your camera doesn’t have them then you need to talk to LInhof service centers.

I was just describing the process of testing any camera's GG against the film holder. Mine doesn't need adjustment.

 

[Andrew Sillett]

 

[Andrew Sillett]

The picture above was taken at f2.5

One last question, please: Nicholas Linden said you can remove the fresnel to the outside of the glass. Does this mean on top of the GG? And if so, won't that cause the same mis-focussing problem?

 

[removed account4]

Have you used this camera with any other lenses and was the focus off ? Chances are you disturbed your focus she moved or the camera moved when you put the film in, If you have a lens that you don’t have focus error do a test shot with the lens wide open. I had a vitax (3.8 ) was tricky to focus. A suggestion that used to be included with wollensak veritar lenses was to focus with the lens stopped down then after it’s focused open the lens up. Worked very well. Also helps to have subject practice sitting still. Kids move and move and .. without realizing it
Good luck with your lens and don’t forget to have fun..
John

 

[Andrew Sillett]

To answer your question, jnatz: I managed to focus with another lens, the standard 152mm Ektar, but I usually had to stop it down to get a sharp subject. Would have been a sound idea to test it, but I think the problem was the fresnel putting the GG on the wrong plane by a few milimetres

 

[removed account4]

To answer your question, jnatz: I managed to focus with another lens, the standard 152mm Ektar, but I usually had to stop it down to get a sharp subject. Would have been a sound idea to test it, but I think the problem was the fresnel putting the GG on the wrong plane by a few milimetres

just making sure you weren't taking something apart that didn't need to be taken apart
sometimes people put the fresnel in upside down and it screws up the focus plane.
a lot of people tinker with their lenses and camera backs because they are interested in
seeing them apart or want to clean something or whatever, and many of these folks, well
they reassembled said lenses and camera backs wrong and were too embarrassed to bring them
to a repair shop to fix their error so they sell them. maybe this happened to your camera.

my comment about kids was in relation my own, and having worked in a portrait studio .. slow shutter speeds and fast lenses are kind of useless until a kid is maybe 16 LOL

no im not passing shade on do it yourselfers, im also a goofball like the people who I described above. first times I took my speed graphic and graflex slr apart to do a FP shutter speed calibration I didn't know the shutter had to be on "0" when you did everything ... so when I closed them up to use after I adjusted the speeds myself, well, the curtain never cleared the film gate. I almost brought them (yes I forgot the first time and re-did it the 2nd time to a 2nd camera) to a shop in a box in pieces and asked the guy to reassemble it for me because I was such a goofball. then I realized what I did and had a happy ending.

hope you have successes ...!

John

 

[hashtagquack]

The picture above was taken at f2.5

One last question, please: Nicholas Linden said you can remove the fresnel to the outside of the glass. Does this mean on top of the GG? And if so, won't that cause the same mis-focussing problem?

Yes you can. As long as it doesnt disturb the position of the GG. So just place on top on the side closest to your eye. If you need to check you can focus with a loupe without the fresnal and recheck with the fresnal in placwe.

 

[NB23]

I put a nice one on a Speed Graphic and tried it out. Then I gave the lens away.

Huge mistake.