Agfa 80mm F4: Process Lens

I did a little more informal testing: It is resolving at around 114 cycles per millimetre( at 1-1)

I tried to test for chromatic aberration but I am not sure I was doing this correctly as the results are to my inexperienced eye good. The pictures are of a microscope calibration slide mounted at 45 degrees over white backing:

at 1-1




at 2-1





100% crop at 1-1






100% crop at 2-1

Last night I worked with the lens a lot. It does seem to have a very thin depth of field and I soon found with the full frame camera I was setting the capture to APSc to get the best shots. I tried the MFT camera and I was getting decent shots with out stacking when the coins were about the size of a 1 cent piece. Once I got to about half sized magnification, although the pictures were perfectly Ok there was some loss in IQ. As I had read on the internet it looks like this lens is optimized for 1-1 through 2-1 magnifications.

For both my cameras I am limited to F 5.6 I thought F8 would work on the Full frame camera but the results were not good. I am not expert with such lenses and what I am saying next seems wrong to my limited understanding of optics: The lenses performance suggests to me it has an extremely thin DOF at 5.6 ( more so than other lenses at the same aperture). Using my depth of field calculator at F5.6 the DOF is 0.387mm in depth, and at 2X magnification it is 0.223 mm( if I have done my calculations correctly)

This is the sort of camera it was designed to be used on( 1970's-80s vintage) I nicked the photo from the web:




I like the lens it has a low profile... it is light in weight, but seems robust. It has nice definite click stops. On the set up I was using the F stop markings were were not visible so It was nice to be able to simply turn and count the clicks to set the aperture. Some lenses in comparison have indefinite clicks and I am less sure of which aperture I am setting( means resorting to a mirror to see the markings.

some cons.
1. It doesn't have a filter thread( some of my lighting set ups can't be used)

2. It flares really easily, back lighting is a definite no with this lens. I noticed the flaring when I was adjusting a coin for composition. Just the light being bounced into the lens from my hand was enough to cause a huge loss in contrast. this is where a filter thread would be useful as one could screw in a Lens hood.
I will look out for another, one of the local camera specialists ( the Leica shop) re-coats lenses with modern lens coatings. If I find a second example cheaply I will see what that shop can do with this lens.

3. It needs a lot of extension for 1-1 and with 2-1 I had to add an extension ring to my bellows.

Here is some reduced images from last night Camera in this case is Olympus OMD-EM10II (MFT camera). I think the lens would perform better on APSc with larger pixels. It may well be that F8 is the optimal aperture for this lens.

Others with more experience may know more but I think this is a stacking lens ( a baby ARD 75mm perhaps? I have not used the ARD so I am guessing).

I ended up buying one of these and will test when it arrives. Thanks AK for the link to ebay UK seller.

Looks good. I'm patiently awaiting the arrival of mine to test it out.

I retested the lenses resultion. As I noted earlier I wasn't happy with the rig set up. Using the same equipment I tried again. I first used a 10X microscope objective and I am now sure that objective is not good. I then switched to a five times objective. This is the full sized photo with the agfa set to 1-1 magnification and the image from the agfa projected onto the 5X microscope objective. Taken at F 5.6)





I used the Olympus OMD-EM10II camera as it has a higher potential resolution than the Sony A7rII. The next shot is the centre crop from the above photo. On the optical rig I set up the results show the lens is at least capable of Group 7 element 1 perhaps element 2 and I suspect with an improved set up( not in my budget for now) The lens will show even more potential. This means the lens is resolving at a frequency of 128 cycles per millimeter ( a cycle is one black line followed by a white line).





I found a F4,5 version of the lens at a shop in Graz. It arrives in the next couple of days. I suspect it will be equally as good

I received the F4.5. It is very much like the F4. My guess is the F4 is the later version as the 4.5 does not have a 4.5 marking on the aperture ring. Only the the first stop( 5.6) is marked. I don't have the time to do the measurements... but it may well be exactly the same lens.... and the 4.5 rating was incorrect. This lens would have been used at a very small aperture so the manufacturer may not have been that concerned with decribing the maximum aperture accurately

One annoying thing with the latest example is that it had been installed in a home made Linhof board for a view camera. I knew this when I purchased it. I had to cut off the board and that's when I had discovered Some idiot had epoxied a locking ring to the lens mount( the board had been glued to that locking ring.
I suspect the locking ring, that is now fixed permanently, to the lens mount wasn't the right size.

It worked out as I discovered I could attach the camera mount end of an old Minolta extension ring set( the same type some use to adapt Printing nikkors) by friction fitting it. The funny thing is that camera mount section actually came with an ebay purchase minus the rest of the extension ring set.I am so glad I didn't throw it way.

I had the resolution test rig set up and it is, at 5.6, just a smidgen better than the F4.


The Extension ring mount looks like it was made for the lens and attached locking ring so I won't be doing any more testing until my application of epoxy resin has cured.
In my research I had read that large format photographers adapt this particular lens because it is sharp and has an image circle that easily covers large format film. My experience should be a warning for any one looking at getting an example that has been adapted for fitting to a view camera( you will at least know what to ask a seller)

I received my AGFA 80/4 Repromaster today and took an aperture sweep of the 1949-S Cent I used for my 100mm shootout. The lens had some issues at f4 but was really good at f5.6 and f8 at 0.7:1 magnification (f9.5 and f13.6 effective). See the f5.6 shot below. You can download the full size original at:

http://s943.photobucket.com/user/rp...?sort=3&o=0.

The lens is extremely sharp and shows no discernible long-CA at f5.6 and beyond. I will be including it in my 80mm shootout and expect it will do very well.