Hello,
I am going to buy a setup for doing visual and photometry.
I would like suggestions, I am trying to avoid a MM camera due the costs but if I realize that 2600MC is not a good fit for photometry I will have to reconsider.
I would like to start doing follow ups in an advanced level but if using 2600MC be an impeditive I would like to know before I spent my budget in a wrong tech.
Regards,
Silvio
If you can afford the 110GTX you may buy any camera you want! What mount are you consideringâhave? When you type âvisualâ do you mean âcolor pretty picturesâ or do you mean using your eye with an eyepiece?
You should be able to do photometry with the MC version of the camera.
You should review the AAVSO photometry guide for CCD/CMOS (MM) and the DSLR manual which would give you the basics of using a (MC) CMOS camera for photometry.
It is up to you to decide. Of course, ask more questions if needed.
Jim (DEY)
hanks James for your assistance.
Good part of my budget is for the scope that is why maybe some accessories I can leave for next year. I want buy a camera that will allow me to do all type of photometry possible, if I had to wait that is fine.
I am considering the AM5N I saw that is a good choice for the scope.
For Visual I meant observing but I want to do astrophotografy too.
I had many chats with ChatGPT -:)))) He said 2600MC would allow me to do a serious photometryâŚ. I guess he was wrong -
Not at all. The ASI 2600MC is a one shot colour canmera and therefore can be used very effectively for photometry, just as DSLR cameras can. The big advantages of the 2600 are that it can be cooled and that it has 16 bit ADC.
There is another advantage of OSC cameras: data from the three colour channels are recorded simultaneously making transformed photometry ârelatively easyâ for targets such as pulsating variables where the colour index changes continuously throughout the cycle, even for short period variables.
Of course, if you had a mono CMOS camera and filter wheel and used photometry software such as VPhot or Phoranso, those apps will allow you to do transformed photometry.
If astrophotography is to be an important part of your observing, go for the 2600MC - it takes fantastic images.
Thanks Roy !
Let me ask you something elseâŚ
What types of photometry are up there ?
Would I be limited to do some kind of photometry using a MC camera ?
If I buy a spectrometer in the future, is this MC camera work fine with it ?
Regards and thanks again !
Silvio
Hi Silvio,
You would need to be careful with stars that do not emit like black bodies, for example very red stars and stars with emission lines, if you use a colour camera. I am not a spectroscopist, but I believe you can perform spectroscopy with a colour camera. However I suspect you would have less sensitivity and there may be other issues, but try to get an expert opinion.
I believe that the âdifferent types of photometryâ referred to different wavebands. In professional astronomy, photometric measurements are usually done with some standardized filters, like Johnson-Cousins UBVRI, which are not exactly the same as RGB filters used in color cameras (thoug V is somewhat close to RGB green). So the observations are reported differently. If you plot any light curve using VSP, it will display different symbols corresponding to specific types of filters that the observers used.
As for spectroscopy, I guess thereâs nothing wrong in using a color camera, but keep in mind it has really no advantages whatsoever when compared to monochrome. When observing very cool stars, I struggle to get decent signal in the blue part even with a mono camera, and with color it would be even worse since only one pixel out of four is sensitive to blue.
HumâŚok..thanks for your helpâŚvery appreciated !
Krzysztof, if I decided to buy a 2600MMâŚwhat are the least filters I should buy to do a photometry and astrophotography ?
Is this corrrect ?
Wheel of filters
Johnson v â Photometry
Johnson Luminance L â Astrophotography
Johnson RGB â Astrophotography
All filters of 36mm.
Would be good to get a sloan r ?
Regards,
Silvio
I know little about astrophotography, but as far as Iâm aware most people use LRGB sets. You technically can do photometry with these filters as well, but the observations have to be reported separately (see the manual)
Astrofotographers also like to use narrowband filters for imaging nebulae- if you decide to try these, H-alpha would be the one youâd like to have the most, than O III, and eventually S II
Now, for photometry different filter systems are used, one of them is Johnson-Cousins and it consists of five filters, but you donât need to buy the whole set at once. If you want to start with just one filter, then the most important one is âVâ (when you see a magnitude of a star in a catalog, it usually refers to V magnitude). The next one is âBâ. Having both âBâ and âVâ allows you to measure the most commonly used color index, namely B-V. Then you can add others if you wish.
I donât know about the SLOAN system, but I guess in this case you should also start from the âgreenâ one. Also, I see no point in mixing the two sets, since all the color indices are calculated from magnitudes measured within the same system. So, choose one system you like (Johnson, SLOAN, or whatever) and once you have all the filters of this system and some money to spare, you can think about another set.
And actually, I donât know if thereâs anything wrong in using Johnson BVR filters (or corresponding SLOAN filters) for astrophotography instead of RGB, if you donât want to spend money on two separate sets. I wonder if anyone tried? The colors might be a little different, but who says you canât do it?
I Think I will see the costs of these filters below:
Johnson L - Luminance
Johnson B - Blue Channel
Johnson V - Green Channel
Sloan r - Red Channel
With L filter looks like I can save up to 60% in the exposures time
This way I will have B and V as you advised me earlier
Using the âSloan r + Johnson Vâ I will be able to do photometry for Pan-STARRS (Rubin Observatory/LSST) and the Zwicky Transient Facility they are using sloan filters but looks like I can use Johnson V instead of sloan g.
If all that be too expensive I will keep my original idea of 2600MC.
What do you think ?
As I said, I would stick to one photometric system if I were you, so either Johnson-Cousins or SLOAN (preferably the former, as it is more widely used among amateurs). But again, thats your money, so you decide. And good luck on your new adventure!
thanks a lot for your helpâŚ
The pleasureâs mine. We are always happy to welcome new observers
one more thing, would you recommend a photometry training from someone with good reviews in the community ?
Silvio,
Be careful with your filters if you get a monochrome camera.
You referred to âJohnson Lâ as a luminence filter. It is not a luminence filter but a mid infrared photometric filter.
A true luminence filter is often sold in a set with other astrophotography filers as LRGB.
Ow boyâŚdidnât know thatâŚI will ask that to the reseller that is helping me with the BoM.
Tks for the heads up.
Iâm sure youâll find plenty of experienced observers here, so donât be afraid to ask questions.
And sorry, it didnât occure to me that you were actually confusing âLâ with âIâ. Thatâs a completely different thing and it would be a shame not to realise it.
Not worries⌠you were very helpfulâŚ.
Thanks again for your help !
I have very recently started on doing spectroscopy, so my experience is limited, but i was involved in a lengthy thread about which camera to use. I had taken a spectrum with a Star Analyzer 100, a Newtonian telescope, and a colour camera. I had posted this result in the RSpec spectroscopy forum. The discussion involved some very experienced and knowledgable people who pointed out that the colour camera Bayer matrix over the sensor created an odd shape to the spectral curve that would be hard to correct. As I am trying to acquire accurate scientific data, it was clear that a colour camera was not the best choice for spectroscopy. Robin Ledbetter had pointed me to a review of two mono sensors where Christian Buil compared the 533M and 585M sensors and while the 533 was good, the 585 was better.I then purchased a 585M. Have not had a chance to do any spectroscopy yet, but a few astrophotography images as a test have impressed me.
Clear skies,
Rick