#TS OPTICS PHOTOLINE 72MM F 6 FPL53 ISO#

The 60mm, f/6 air-spaced doublet is fully multi-coated and composed of highly desirable low-dispersion FPL53 glass and a matching lanthanum element for excellent colour correction for both visual and photographic applications. However, for an achromat of typically encountered sizes to have an acceptable level of colour correction, an optician needs to make the instrument’s focal length at least twelve times the diameter (or aperture) of the lens, which immediately explains the long tubes of classical refractors. In fact, the use of crown and flint types of glass to fashion a so-called ‘achromatic’ lens capable of bringing two wavelengths of the colour spectrum (usually red and blue) to focus dates back to the British inventor Chester Moore Hall, in around 1730. I quickly learned that a simple compound lens composed of a sandwich of two types of glass with opposing dispersive (prismatic colour-making) qualities only goes a limited way to cancelling out this annoying inherent defect of refractors. Thus I had my introduction to the bane of simple lens-based instruments: chromatic aberration. While I was immensely proud of my four-inch, f/5 refractor, its images of the Moon and bright planets were surrounded by a vivid purple halo. I built my first telescope out of a 100mm diameter, two-element government surplus lens of 500mm focal length in the early 1970s. I know it's not much but hopefully this can be of help to some.For casual terrestrial observations and quick looks at the Moon the TS PhotoLine 60mm, f/6 is quite at home on a sturdy photo tripod such as the author’s Manfrotto 055 shown here. When time permits I want to do some more testing with this configuration, how long a single unmodded sub has to be to match a modded sub for example. Just a slight stretched, no other edits were made.

The 27min unmodded stack is imo very similar to the 180sec single modded image in terms of data capturing.Īs I said before, yes it is possible imaging with an unmodded dslr+narrowband(ha) but is it worth it? Well that's up to you, personally if I wouldn't have a modded dslr I would rather use that imaging time to capture extra RGB data.Īs extra I made a separate stack of 28min(7x240sec) RGB data, without Ha filter, taken with the stock d610. The amount of data gathered with the unmodded dslr just can't match the modded dslr. Noise is slightly improved for the unmodded stack with the use of calibration frames. The image was slightly stretched just as in the single subs, no other editing was done.įirst observations: roughly the same as with the single subs. In both stacks all the calibration files were added.

For the d90 I selected 9 random images to get the same total amount of exposure. Next stacking: I was only able to get 9 images with the d610 so it gave me a total of 27min. The amount of detail/data captured is perhaps one of the most obvious differences. I believe this is because of the low SNR and with 4 or 5min exposure it would probably be a lot less. No other editing was done.įirst observations: Yes it is possible to image with an unmodded dslr + Ha filter, there is actually some data even with such a low exposure for Ha!

#TS OPTICS PHOTOLINE 72MM F 6 FPL53 ISO#

I decided to use exact the same settings on both cameras so not compensating for the light loss with the unmodded camera, exposure and iso were the same.Ĭamera settings for both were: 180sec subs at iso1600įirst the single subs: These are the raw images with a minor stretch to reveal details.

Guidescope: TS-Optics Optics 50 mm DeLuxe Mini

Optics: TS-Optics Photoline 72mm f/6 FPL53+TSflat72 Camera: modded Nikon d90(1 filter), stock Nikon d610 During my first narrowband imaging a couple weeks ago, I decided to do a short test with my modded d90 vs my unmodded dslr d610 and 7nm 2' Baader Ha filter.

Ts optics photoline 72mm f 6 fpl53