7 replies to this topic

[DMala]

Well, for the series of having Night Vision fun with the classic telescopes that I already happen to have, yesterday I also set up the above Vixen-made little scope from the early 1980s with a 1.25" visual back, diagonal, my PVS-7 in prime focus, the Astronomik 12nm Lumicon Night Sky filter, a period-correct heavy duty  Vivitar tripod (still a bit shaky, unfortunately), and a Vixen fine motion adjustment tool between the tripod plate and the telescope.

 

If interested see a discussion on the 9VR here: https://www.cloudyni...co-9vr-60mm-f5/

 

I used my now obsolete Samsung Galaxy S5 and el-cheapo cell phone adapter, using the android app "Snap Camera HDR" that has a night vision/HDR mode that seems to allow averaging up to 7 shots. With my phone and based on empiric tests max ISO seems 1600 and longest exposures so far seem up to 1/10". 

 

I spent a good part of the evening continuing to familiarize myself with the app menus, using Orion as target. Nothing special until the end, when I switched to the Rosette nebula after discovering how to edit "on the fly" some parameters of the 4-shot series I was taking, prior to having them averaged into one final image. I still have to figure out several details on how to do that but I found my best result far from perfect but encouraging, considering the small aperture of the telescope, the old technology of the phone camera, and a shaky tripod (but I had a 2-sec timer prior to taking the shot series). Focusing is also often off: even when set to infinity, the camera keeps adjusting and/or screwing up focus. But out of many shots I got two better ones, and this is the best. Once I got it, I installed the Pentax 50mm camera lens on the PVS-7 and I made the low-power observations of my other post from last night.

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[Eddgie]

Thanks for the info on the app. I may try it.

 

I can see some nebula, but it could be that you need to move into a narrower band pass filter.

 

You are making progress though and I am sure that it is fun getting to do new things with your vintage scope!!!

[DMala]

Thanks for the info on the app. I may try it.

 

I can see some nebula, but it could be that you need to move into a narrower band pass filter.

 

(...)

In fact, you are right about the need for a narrower band pass filter to better visualize the nebulosity: I made a mistake in the original post above. For the pic I used a Lumicon Night Sky filter, not the Astronomik  12nm H-Alpha. The latter blocks off too much light for the 60mm lens f5 and for the limited sensitivity of my cell phone camera. 

 

If you decide to try Snap Camera HDR, it comes in a free version that only requires to be in plane mode when using it. Good enough to get a preliminary opinion of it. I then bought the full version for very few $$. PM me and I will share the sub-menu selections I came up with, there are multiple layers.

[Eddgie]

Ah, that explains it.  I was a bit surprised that not much nebula was showing, though I felt like I could see a bit. 

 

The size of the scope is unimportant.  For filtered work, a faster scope will be better, but even at f/5, you should see considerable nebula with the 12nm.   I would pop that puppy in and go for it.

[GeezerGazer]

The size of the scope is unimportant.  For filtered work, a faster scope will be better, but even at f/5, you should see considerable nebula with the 12nm.   I would pop that puppy in and go for it.

I agree with Eddgie.  You might see less visually with the bandpass filter, but the camera might pick up what you cannot see.  1/10s is a pretty fast exposure for NV, but might be sufficient with the 7 averaged frames. I'd definitely try the 12nm.  

 

I have used a 12nm and 7nm with a 60mm finder at f:3.8 that works pretty well, but my finder shows more curvature than your Tasco.  I think you just have to try and see what happens.  Overall, I would say that you made a very nice first photo and encourage you to keep at it.  

[DMala]

(...)  I think you just have to try and see what happens.  Over(...)

Thanks. Since right now my focus is to become more familiar with the phone camera app, and just to get a preliminary feeling of the effect of the various filters, the little Vixen/Tasco is a quick and easy option to avoid spending time on more complicated setups.

 

Once I feel more comfortable with my night vision and photo setup, and the weather allows longer outdoor sessions considering some health issues I have, at my South NJ location I plan to switch to my 6" f6 Newtonian on a pier mount, and see if a Paul Rini .5X reducer I have around would happen to work.

[Stargazer3236]

I get better results with my AT60ED APO and ASI294MC camera. There is so much hype about NV imaging, but unless you spend big bucks on NV, CMOS is the way to go! Here is the Rosette 23x8s, Gain 450

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Edited by Stargazer3236, 20 January 2019 - 08:34 PM.

[DMala]

Thanks, not sure if that was an encouragement or a discouragement but I am sure the intention was good..... I actually think the biggest difference is  1/10"x4 (mine) Vs 8"x23 (yours), and from that standpoint I continue to think I did not do too bad for the very minimal extent of exposure my phone allows..... maybe we should re-consider if and when I get a phone capable of integrating multiple longer exposures.

Edited by DMala, 20 January 2019 - 09:42 PM.