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Understanding STF-8300M & STT-8300M

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#1 mmalik

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Posted 12 January 2013 - 10:05 AM

I come from DSLR side of things; bit new to CCD and trying to decipher what SBIG has to offer in terms of STF-8300M... & STT-8300M... (Monochrome) cameras. My questions below if you can help shed some light:


•Which package (listed below) makes sense, practically speaking, in terms of what all one might need after overcoming the CCD learning curve? In other words, is it good to take combo vs. piece meal approach when buying CCD equipment?

•Between FW5 vs. FW8, which is recommended or more practical filter wheel?

•What brand filters SBIG uses in the combo packages? It is OK to get SBIG filter combos FW5/FW8? If NO to SBIG, which filters would you recommend? I presume empty filter wheel spacers can be filled with any brand filters, correct?

•What’s the major difference between STF-8300M and STT-8300M? Which one may be better?



I think you get the point; your insights into what makes sense in terms of getting started with SBIG CCD will be greatly appreciated. I don’t want to put too much emphasis on $ just yet, getting to know SBIG CCD equipment being the main goal here; would like to understand what makes sense before delving too much into what might be expensive or cheaper. Please fill in the blanks as I may even not have asked all the right questions. Regards


STF-8300M...................................................$1,995.00

STF-8300M OAG FW Package..........................$3,695.00
-STF-8300M camera
-FW5 filter wheel
-Off-axis guider

STF-8300M Self Guiding Package w/ ST-i........$4,195.00
-STF-8300M camera
-FW5 filter wheel
-Off-axis guider
-ST-i Autoguider (mono or color option)

STF-8300 Pro Package w/ ST-i........................$4,595.00
-STF-8300M camera
-FW5 filter wheel
-Off-axis guider
-ST-i Autoguider (mono or color option)
-36mm LRGB Filter Set
-36mm H-alpha Filter

STF-8300M Pro Plus Package w/ ST-i...............$4,995.00
-STF-8300M camera
-FW8 filter wheel
-Off-axis guider
-ST-i Autoguider (mono or color option)
-36mm LRGB Filter Set
-36mm Clear H-alpha Filter
-O-III Filter
-SII Filter


STT-8300M...............................................................$3,695.00

STT-8300M Standard Filter Wheel Package..................$4,490.00
-STT-8300M Camera
-FW8-STT Standard Filter Wheel

STT-8300M Standard Filter Wheel Pro Package............$5,185.00
-STT-8300M Camera
-FW8-STT Standard Filter Wheel
-36mm LRGB Filter Set
-36mm H-alpha Filter
-O-III Filter
-SII Filter
-Clear Filter

STT-8300M Self-Guiding Filter Wheel Package.............$5,290.00
-STT-8300M Camera
-FW8-STT Self-Guiding Filter Wheel

STT-8300M Self-Guiding Filter Wheel Pro Package ......$5,985.00
-STT-8300M Camera
-FW8-STT Self-Guiding Filter Wheel
-36mm LRGB Filter Set
-36mm H-alpha Filter
-O-III Filter
-SII Filter
-Clear Filter


Note: My DSLR work here....

Attached Files



#2 broca

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Posted 12 January 2013 - 10:36 AM

The STF-8300M has a faster download speed with improved electronics. Here is a helpful thread than may answer many of your questions.

I don't know where you are in regards to equipment you may already have. The combo packages may be a good value, but, if you already have an autoguider, the combo packages may be redundant.

If you have the funds I'd go with the FW8, that way you can have all commonly used filters, LRGB, Ha, SII, and OIII at your disposal.

Again, if you have the funds the Astrodon filters come highly recommended. They come in 36mm and, I believe, will fit the FW by SBIG. I've read people having trouble with "halos" with Astronomik filters. But I've also seen some really nice images with them!
I came over from using a DSLR ~1 year ago. When I pulled the trigger I went with the QSI 683ws. At the time I was reading more favorable reviews for the QSI.
You have a lot of nice images you took with a DSLR. You are going to nail it when you do CROSS OVER :gve:.

#3 CJK

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Posted 12 January 2013 - 02:52 PM

All the filters included with the packages are by Baader.

Astrodon makes 36 mm unmounted filters to fit the FW5-8300 and FW8-8300, but at present, only the LRGB and 5 nm H-alpha are available.

I just ordered an STF-8300M myself. I also bought an FW5-8300 + (Baader) LRGB filters package because I'm just getting started in all this stuff. I will probably order a H-alpha filter in the near future, though it'll be an Astrodon filter rather than the one from Baader.

-- Chris

#4 Peter in Reno

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Posted 12 January 2013 - 04:09 PM

Astrodon makes 36 mm unmounted filters to fit the FW5-8300 and FW8-8300, but at present, only the LRGB and 5 nm H-alpha are available.


Astrodon do make 36mm Oiii and Sii in both 3nm and 5nm.

http://www.astrodon....ers/narrowband/

Peter

#5 pfile

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Posted 13 January 2013 - 12:32 AM

i just got the STT-8300M and self-guiding filter wheel FW8-STT. i opted to go for astrodon filters. imho they are higher quality than the baader filters.

i guess the STF-8300M requires a different OAG setup, but IMHO this is a must if you are using a large reflector that may suffer from mirror shift issues.

you're going to be shocked at the quality of the data from one of these cameras vs. the DSLR. i still can't quite get over it :)

#6 CJK

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Posted 13 January 2013 - 01:59 AM

Astrodon makes 36 mm unmounted filters to fit the FW5-8300 and FW8-8300, but at present, only the LRGB and 5 nm H-alpha are available.


Astrodon do make 36mm Oiii and Sii in both 3nm and 5nm.

http://www.astrodon....ers/narrowband/

Peter


Aha -- I guess they were only out of stock at the site I checked. Didn't think to check Astrodon's site directly.

-- Chris

#7 mmalik

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Posted 13 January 2013 - 02:00 AM

I just got the STT-8300M and self-guiding filter wheel FW8-STT. I opted to go for Astrodon filters. imho they are higher quality than the Baader filters.


Thanks Steven/Chris/Peter.

@Pfile, I have updated the first post to include STT-8300M packages. Some follow-up questions:

1. Which STT-8300M package did you buy and from where?

2. Does 'STT-8300M Camera w/ Self-Guiding Filter Wheel Package ' at $5,290.00 come empty or filled with filters? I presume it comes empty and probably this is the one you bought?

3. Is auto-guider camera, e.g., ST-i still required with 'STT-8300M Camera w/ Self-Guiding Filter Wheel Package'?
Edit: After some researching, looks like auto-guider camera is built-in to the filter wheel.

4. Could you post some pictures of your STT-8300M, especially filter wheel carousel, if possible? Thx

#8 mmalik

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Posted 13 January 2013 - 08:17 PM

I guess not whole lot of STT-8300M... users out there?

At first I was thinking filter wheel might be built-in to STT-8300M but that's not the case; FW8-STT Self-Guiding Filter Wheel is a separate and quite bulky looking unit (apparently somewhat similar older FW8 Filter Wheel). I did some searching and found this helpful STT video....

Can someone comment on how bulky/heavy does it get with STT-8300M+'loaded' FW8-STT Self-Guiding Filter Wheel? Some pics of this setup will be very much appreciated. Regards

Note: I have updated first post with some specs comparison.

#9 pfile

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Posted 13 January 2013 - 09:29 PM

to my knowledge there are about 5 people using the STT-8300M who have popped up in various forums. Jerryyyyyyy has one as well and he's reasonably active here.

anyway:

1. i bought the empty one from OPT and a set of astrodon filters at the same time. be careful installing them - the filter wheel does not need to be super tight. i managed to crack the edge of one of the filters... duh.

2. i think that one is empty. the one with baader filters explicitly says that it is empty.

3. you do not need a separate guide camera if you have the FW8-STT. the guide chip, pickoff prism (and a focal reducer, i think) are built into the filter wheel 'cover'. this filter wheel is too thick to use with canon lenses, so if you want to do that you have to get the non-self guiding filter wheel as well.

i can post some pictures but right now the camera is on the telescope and it's dark. i also have an AO-8 on there but due to software problems it's not yet doing anything.

rob

#10 pfile

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Posted 13 January 2013 - 09:31 PM

oh yeah, here's my biggest project with the STT-8300M and an AT10RC:

Posted Image

#11 korborh

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Posted 13 January 2013 - 10:59 PM

STT has RBI. STF does not.

#12 mmalik

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Posted 14 January 2013 - 12:07 AM

I can post some pictures but right now the camera is on the telescope and it's dark.


No rush and no need to take things apart for pics; may just post telescope mounted STT/Wheel for perspective when you can.

Looking at the video..., STT looks ok, but filter feel seems quite bulky/heavy? How heavy/bulky is STT/guided-wheel setup in your opinion (flexure being the concern)?

Your M81 looks nice. Thx

#13 mmalik

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Posted 14 January 2013 - 12:10 AM

STT has RBI. STF does not.


I had to Google RBI; can you please explain what it is for us DSLRers? Thx

#14 korborh

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Posted 14 January 2013 - 12:44 AM

RBI (Residual bulk image) - basically a residual of electrons trapped in the CCD substrate which leak into the next image leaving behind a ghost image. More here link

STT specs indicate RBI pre-flash to reduce this effect. The RBI removal features are found on the more expensive cameras like FLI.

This is new information to me as well, as I am currently researching my next CCD camera.

#15 Peter in Reno

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Posted 14 January 2013 - 12:59 AM

RBI should be easy to fix for all cameras. All you have to do is put a 10 second or so delay in between subs. After 10 seconds, RBI is already gone before exposing next sub. Or you can use dithering. It typically takes at least 10 seconds to dither before exposing next sub. Dithering is useful for removing hot/bad pixels during stacking.

Peter

#16 Konihlav

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Posted 14 January 2013 - 03:23 AM

dithering is NOT the way to deal with RBI. It in fact makes things even lot worse than without dithering as it makes it to show some dimm ghosting that would not be visible if every sub is exactly on the position every time.
The only way how to correctly fix for RBI is a controlled IR preflash.
My opinion on RBI in KAF-8300 is that 99% of users with camera with KAF-8300 without IR preflash will face every other issue than RBI - that would be the last one, least important, barely visible/notable. It might be an issue only for science data I guess. For our amater astroimaging it's enough not to take flats with EL panel prior taking light frames and not to cool on 100% power usage of the camera. I find it particullary hard to even detect RBI by normal users.

#17 Peter in Reno

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Posted 14 January 2013 - 10:17 AM

I was referring to mimic delay when using dithering. In my case dithering typically take 20 to 30 seconds and that's plenty of time for the ghost image to disappear. If dithering takes 5 seconds or less, then you are correct, the ghost image may remain there. I've been dithering for the past three years using two different cameras without any issues regarding to RBI. If you think 20 to 30 seconds is not long enough to remove ghost images, then I may be incorrect about my previous statement.

Peter

#18 John Wunderlin

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Posted 14 January 2013 - 11:58 AM

Thanks for your post Peter! I was wondering why sometimes I have RBI show up and not others. Most of the time I dither so it's not a problem. I hadn't heard that a delay would help the RBI issue before. Good to know!

#19 Peter in Reno

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Posted 14 January 2013 - 12:20 PM

John, you are welcome.

Peter

#20 pfile

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Posted 14 January 2013 - 05:15 PM

here's a picture of all the junk attached to my AT10RC.

Posted Image

#21 John Wunderlin

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Posted 14 January 2013 - 05:40 PM

I did some more googling and it sounds like RBI can hang around for quite a while depending on CCD configuration. I may do some testing tonight if I have time after my date with a couple of comets :)

#22 mmalik

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Posted 14 January 2013 - 07:49 PM

Here's a picture of all the junk attached to my AT10RC.

Posted Image


That's lot of junk, good junk in a way; very long imaging train though. Does it not cause flexure in the system? I think you could get rid of AO (Adaptive Optics [had to Google it to figure out what it was…]) to make things simpler; but then I have never used one or know if it really improves things? How heavy is ‘FW8-STT Self-Guiding Filter Wheel’; I have yet to find specs on this unit (please provide specs link if you know?). Thanks for the pic. Regards

#23 pfile

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Posted 14 January 2013 - 08:15 PM

i think the camera is something like 4 pounds and the filter wheel 2 pounds. but i will check. flexure is an issue especially with the AT10RC but the OAG takes care of most of that.

the idea behind guiding with the AO is that you can move a small piece of glass much more quickly than the whole mount, so in theory it can react faster and even compensate for bad seeing to a certain degree. my mount has really bad PE (some very fast spots) that the guider/mount can just not keep up with, so i thought maybe the AO could solve my problem.

the best solution to the problem would be software bisque or astro-physics, though :)

#24 mmalik

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Posted 14 January 2013 - 08:43 PM

...flexure is an issue especially with the AT10RC but the OAG takes care of most of that.


Misconception in my opinion; yes OAG may take care of guiding related flexure but it wouldn't make your sensor perpendicular to the optical path. You'll still have oblong stars in the image regardless. Thx

#25 pfile

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Posted 15 January 2013 - 01:35 AM

i guess i was referring to differential flexure. this type of scope is almost impossible to collimate "perfectly" in every attitude because the weight of the camera, focuser, etc. causes the mirror to shift as the OTA position changes. i'm not sure if there is a camera and focuser light enough that this is no longer an issue.

in practice the effect is not that bad. this could be due to using a small-ish sensor. not sure. also in this type of design, without a flattener at least, the stars at the edges of the field are out of focus anyway. it's coma-free but has relatively large curvature.






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