mercoledì 10 gennaio 2018

Bleaching a Yellow Takumar

Super Takumar lenses are known to get yellow with age. Actually, the issue is common to many radioactive lenses.
The Super-Tak 50.1/4 in my possession was very yellow, as you can tell from this picture. Note especially that the center is darker: this is because the lens is thicker in the middle. The glass itself yellows, not the coating. A bit of yellow gives warmer images, however such strong yellowing absorbs light and reduces the speed of the lens.


From what I gathered,  the radioactivity is caused by Thorium, used to improve the Abbe Index: Rare Earth elements allow excellent glass (LaK, for example or other Lanthanum based glass). Emitting  alpha particles tint the yellow.
Some people left their lenses in the sun for weeks and they cleared out! Fine, but I didn't want to leave my fine lens exposed to weather events.
I sought another source of UV radiation, so I bought a black light lamp. These lamps emit mostly UV-A and are safe. UV-B would probably be faster in action since higher in energy.

This is how a photograph can look.




I left the lamp close to the lens putting it in a desk lamp with a shade to direct most light down, the swing arm down closest to the lens.
The lens to be cleared is on the back, so I left the lens mostly upside down, but sometimes I turned it for a day upside.

This is how the lens looks after bleaching. Quite effective! Only a slight yellowing remains. I could have prolonged radiation, but am satisfied enough.



domenica 26 novembre 2017

Maratona Fotografica Bergamo 2016

Rainy day, typical rain light. I had choosen the trusty RPX100 which seems to prove more and more as a trustworthy film, not really an APX100, but better than FP4+, some sort of cross-breed.

I developed in Rodinal 1+50 for 13 minutes.
Very fine negatives, shadows and highlights are well balanced.
 Camera: Nikon F90s and various Nikkors.

Nikkor 105/2 focus control:


28mmPC. The shift allowed a unique balanceof the fountain (del Contarini) and the Palazzo della Ragione.


28mm PC, quickly shot "as street" while I was doing the architecture above:

The Devil's Bridge - PanF Rodinal

A lot of people do not recommend PanF and Rodinal together, I find it instead a very interesting combination. The negatives are not very strong, but with a full greyscale, very printable and perfectly scannable.

Mamiya 645;  Ilford PanF 50/18° ISO; Rodinal 1+50;  12' at 20°C


You can acquire a print, poster or home decor for it on Fine Art America.

Rollei Supergrain - Venice 2016

I experimented with the Rollei SuperGrain developer with the rolls shot in Venice, 2016.
Shots are from a Mamiya 645 and the weather was rainy, the light wasn't optimal. Bad conditions for good black & white!

First, Rollei RPX 100 in Supergrain 1+12, 22°C for 6'30" (right time, high temperature).
I find the results smooth with an incredible depth of greys.
I would definitely recommend this Film/Developer combination.




Ilford HP5 in SuperGrain 1+12, 20°C for 6'30" (suggested time)
The results are a bit harsher than the RPX100, however still good.



lunedì 6 novembre 2017

Ikoflex and Prontor SVS repair

The Ikoflex Ic had a stuck shutter, when I bought the camera, I thought it would have been just gummed up, because it has long been on the shelf. I sadly was proven wrong.

To access the shutter assembly, Both lenses need to be removed. The viewing lens comes out completely, while the taking lens detaches its front assembly. The rear part needs of it needs to be removed by accessing it from the back (open the back, remove the light baffle).
Then, by removing the handles of the f-stop, removing the decorative name plate, the whole cover can be removed.
 
The Ikoflex once both lenses and the front panel are removed looks like this:


The Prontor SVS can be easily opened and separated in its essential components. Be careful with the Sync cable, it is tricky since it is tight and secured on the back with a screw.

At first, I tried flushing the Shutter clean (I use Esane, AvGas), but it would still not reliably run.

The Prontor SVS has two delay mechanisms: one is the actual timer for the shutter speeds, the other one is the delayed action of the self-timer which doubles as minimal delayed action when the the flash sync is set to M. X has no delay instead.
The retarders are ingeniously linked together and are cocked together, one of the inventions of the Prontor.

The Prontor without the two retarders:


The flash and self-timer mechanism:


This is the actual shutter timer:



The shutter timer is damaged, the small extension that can be seen top-right is bent. Most probably the shutter stuck and somebody forced the action. I suppose that some customer played with it on the shelf too hard.
However, even when I removed both timers, but even then the blades would stuck half open. While being wet it would work, but not when dry. The real problem though was not friction or dirt, but a slightly bent pin. An U-shaped part needs to be in the right position or the pin attached to the blades, which moves during the shutter action, remains stuck. However it also needs to be able to catch it. The amount is really minimal. Once "bent back" the shutter action moved freely.

Repairing the connecting pin on the timer mechanism was impossible: just trying to bend it back pried it apart. Most often repair-men exchange the whole piece, but alas, A. Gauthier is no more and spare parts are rare, I couldn't locate one. However a very similar Prontor SVS part was found as a donor, perhaps a different revision. The lever was compatible, I exchanged it in the timer.
Opening the timer is tricky and the risk of loosing or damaging the spring is high: I do not recommend doing it if not necessary. I would try to clean assembled.

Mounting all tiles back in the reverse order... and the Prontor worked again... and the Ikoflex is a faithful companion again.

So, remember, don't force shutters if they are stuck!

venerdì 3 marzo 2017

Pisa (FP4 in Rodinal)

Pisa Cathedral seen from the Baptistry


Mamiya 645 -  45mm/2.8 Sekor

Ilford FP4+ rollfilm, exposed 100/21° ISO
Rodinal 1+50, 16' agitation every 2' at 22°C

The result shows a very good control of the highlights (sky) with rich details in the shadow part, what you would expect from FP4+ and Rodinal! A classic combination that always works. Thanks to the 6x4.5 format, the grain is not disturbing and completes the old-school feel.

If you like this image, you can buy it as print, poster, home decor on Fine Art America. Also a very similar color image, shot on Slide Film, is available.

domenica 10 gennaio 2016

Rollei RPX 25 in tour

I took picutres during a motorbike trip in the Alps, sunny days uf August, perfect sky, no filter used.

Rollei RPX 25 developed in Studional (Rodinal Special) 1+30, 4'30" 24°C (equivalent to 7' at 20°C).

Development time looks fine if one considers the general density impression of the negative.

However, once scanned the look is very compressed, the tonal range is really strane. The highlights look incredibly compressed and compensated. There is tonal differentiation, but very little.

This is an image scanned with a flat curve. Above there is a patch of cloudy sky. The sky looks grey as the mountains in the distant haze.






Tweaking the curves slightly, giving it a shoulder in the highlights while retaining black shadows, improves the situation little. Loook at this image, which has more sky.
The clouds remain grey, as the sky. There is no way to get white clouds on a blue sky.

Stelvio - Leica R3 - 50/2
I would not call the results  pleasing. In fact, I consider most of the shots of this trip almost unusable.

This shows that RPX25 is not an easy film and not an easy repplacement to APX25 or Efke/Adox 25.

The mid-to-low tonal range is excellent and shows a high level of detail. I would not recomment just using it at a higher speed (e.g. 32/16 ISO).

Perhaps this developer combination is not ideal, I will attempt further tests.