Ďuro Tomík | Portfolio
Somehow it happened and I have all this at home, together: Takumar SMC 200mm, its successor Pentax SMC 200mm and both of 2x Rear converters: older T6 (black) and newer gray.
I decided to keep only half of this, but obvious question was: what exactly? Logical decision was to keep the newer combination, but it was not so clear for my needs: I am photographing mostly from tripod, land and cityscape and rarely focus closer than dozens of meters. Aperture always 11 to 16.
With this in my head, and also knowing newer Pentax lens is selling for twice the price of Takumar, I've decided to make a little comparison test. Took me two films and two days, after developing first film I saw my focus on one frame was a bit off so I decided to reshoot it. Note here: Focusing 400mm with f8 is really not easy: dim in viewfinder, and critical for errors due to narrow depth of field. I was examining the negatives with quality 8x loupe (Nikon aspherical) and also under microscope with 20x magnification, but I decided to scan it also to be able to share results. I know used scanner is not the best, but images are quite close to what I've seen under loupe.
Conclusion? Scroll down and see pictures to make yours. I enabled downloading every picture in high quality for better comparinson. Or read mine decision, at the end.
Test scene - crops
My beloved test scene - I was searching for it for almost a month. Flat, with details from corner to corner and I can climb on the hill to be in half of height. That's important to keep straight lines but also focusing plane lying flat on the subject.
2x Rear Converter - crop from 200mm
Here's the actual crop with Rear converter. Original - 200mm, red overlay is 200mm x 2 resulting in 400mm focal length. Well, it doubles aperture also, so I was focusing with f8 on my ground glass. I have a splitscreen type and precise focus was quite difficult. That's also reason of bad composing of crop. First shots were not focused well with one lens (off by few metres), so I decided to repeat it next day, but I didn't remembered the exact framing.
Microscope 20x vs scanner
Just for fun: left is a sight from my hobby Bresser microscope (20x magnification if I remember correctly), taken with digital camera I was handholding by ocular. Quality is not the best I know, but for illustration I believe it's OK. Right picture shows actual crop from scanned picture (2400DPI).
Shooting: tripod Wolf 8032 (ash wood, 55mm ball), Cable release, Mirror lock up
Film: Foma 100 professional, pushed to 200 in Ilfotec HC
Scan: HP G4050, Vuescan, negative flat on glass with AN glass on top, 2400DPI scan + Unsharp mask