Thursday, April 14, 2016

Quickie Testing…

This is a quick wrap as I couldn't do much with my camera or anything else, for many reasons. Anyway, I was capable to do one or two tests with my gear, so I decided to put them up here for this week.
I was waiting for a good opportunity to test Voigtländer 20mm lens for panoramas, but time didn't help me out and couldn't really search for a good location to work in. Thus, I've decided to test the panorama in a simple procedure in the guest room at home (which has been recently my operation room!).

Screen capture for the stitched panorama

I have made specific points here, and there are some advantages and disadvantages as it seems. I'll try to list them here in points:
  1. The panorama is a simple 360o, thus it might not be quite accurate for judgement but it gave good indicator I believe.
  2. There was no need to adjust or re-calibrate the VR-head to do this panorama, which is a good point!
  3. However, there was a need to adjust the rotation amount, to 24o instead of 30o. That means a single full rotation will take 15 shots instead of 12 as I used to have it. 
  4. Consequently, for the change of the field of view and the change in the angle of rotation per one shot, the total amount of shots to complete one spherical panorama will be: 15x5 (excluding zenith and nadir points) = 75 shots, compared to 36 shots with Canon EF 15mm fisheye lens. Needless to say, these numbers are multiplied by 3 in case of HDR.

For these points, the procedure includes good and bad points. It is good that I don't have to re-calibrate, but it is bad that I need to change the angles of rotation which will increase the number of shots (and working time) significantly. Thinking about it now, it seems that using the Voigtländer 20mm lens would be significant for panoramas only when the matter comes to using UV-pass filter; simply because I have no UV-pass gel filter to fit my Canon 15mm fisheye lens. The matter of infrared is also a fluctuating one, since I do have 2 infrared filters: one fits Canon 15mm fisheye (gel), and one to fit Voigtländer 20mm (circular), and each one has a specific threshold.
Coming to mention IR filters, I was yet to do another check with my converted camera. I had the chance to pick my gear to work, and voila, when I decided to do that, the sun got blocked out with some clouds. However, it wasn't a big problem, except for the UV photography; just a bit.

Canon EF 100mm macro, f/10, ¼ sec, ISO200.

Ultraviolet photography proved more problematic than I thought, unlike IR photography. However, shooting with a converted camera make it a lot easier. As it can be seen above in UV-Star, the exposure is merely 1/4 of a second, which is quite "long" in terms of handheld shots (I was using a tripod here). That is with rising ISO to 200. On a regular camera, the exposure time could easily be 5 minutes with ISO as high as 800. Anyway, other shots taken that day with UV-pass filter were shaky because of the breeze shaking the stems. One of the problems that one might face when doing UV photography is the fact that some lenses (if not most) are sprayed with a specific coating to reduce UV in order to enhance the image quality; a good feature gone bad! Anyway, I believe with a good sun, the exposure could easily be faster than just 1/4 second at the same ISO. The matter of UV photography is expandable further if we were to discuss artificial lighting and strobes, but let's not come to that right now!

Canon EF 100mm macro, f/9, 30-1sec, ISO100.

Later, I decided to try my B+W IR filter, which has a threshold of 650nm. This threshold means it is considerably a weak filter in terms of IR range, since it allowed some Red spectrum to pass as well. However, on a regular camera with the settings mentioned for InfraBlossom, the exposure time could easily be up to 1 minute if not more. Checking how InfraBlossom processing turned, it seems that such filter is exactly what one would need to do portraiture in infrared photography in general. Anyway, I can't have a final say until I get to test my other infrared filter; a gel filter from Kodak with threshold of 1000nm. This filter is so opaque and on a regular camera and a sunny day, a single exposure under ISO100 can easily reach 10 minutes in time.

Almost under the same conditions as InfraBlossom, but with f/8, the exposure for this shot was 9 minutes, on a regular camera and a sunny day. In comparison, InfraBlossom, would have been taken in 10 minutes at f/9 and a sunny day on a regular camera, when using the same gel infrared filter.

Anyway, I still need to test the gel filter (of 1000nm threshold) on my converted camera. Unfortunately, the only way to do this is with my Canon 15mm fisheye (or Rokinon 8mm fisheye with some improvising). The test is required for my eyes to see for myself the difference in color rendering and processing between 650nm and 1000nm thresholds. On regular cameras, the comparison is already made: with 650nm filter, the image after processing can regain close colors to reality, while with 1000nm filter, the image after processing can be quite bluish after processing.


This is it for now, and I still have some more going on in the current time. Preparations and events that I'm planning to role in, despite my decision previously of being dormant and have some breath. Yet, the group's activity can be quite pressing. 
On the list is testing a real full panorama using UV filter on Voigtländer 20mm, and in a sunny day. Not sure where the location should be, but most probably it would be at work if I can spare some time.
My schedules and sleeping patters are on shift now that I'm starting to fast, and probably it won't be long till I have to stop the fast for the month of Rajab. But it is a good try, and a money savior! However, my tiresome body wouldn't allow me to do much during the day and it would be late at night (after the nap) to work with such projects. Anyway, I'm going to try further, as much as I can.

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