Atik or SBIG

[lensman57]

Hi,

I am looking to purchase a medium format Mono CCD. Does anyone have any experience with SBIG STF 8300 please? I am not going to be able to change my 1.25" filter wheel and filters and I know that Atik 383 L can just about getaway with 1.25" so this will be a factor.

Many thanks and regrads,

A.G

[perfrej]

I think an 8300 based camera with 1.25" filters needs to have the filters real close to the chip - like QSI... The rest will probably need 36mm filters (or 2" for that matter). I use an SBIG ST8300M wit the SX wheel with 36mm unmounted filters and it works fine.

/per

[lensman57]

I think an 8300 based camera with 1.25" filters needs to have the filters real close to the chip - like QSI... The rest will probably need 36mm filters (or 2" for that matter). I use an SBIG ST8300M wit the SX wheel with 36mm unmounted filters and it works fine.

/per

Thank you Per for your reply, if the 1.25" filters are not usable with either of the two cameras then I am afraid that I may have to look for an alternative as I won't be able to afford 2" filters and the corresponding wheel.

Best Regards,

A.G

[swag72]

Have you considered the QSI683? With the wheel so close to the chip I understand that you can use 1.25" filters to about f2.8. Do just drop IKI a line to check, but I'm sure that's right.

Build quality of the QSI is utter top notch.

[NickMorris]

Hi,

I have a QSI 683 and I believe the limitation is F5 for 1.25".  I think that 31mm filters will get you down to F2.8.  I recently spoke to Ian about this and pretty sure I remember correctly but please confirm with him.

all the best

Nick

[perfrej]

1.25 x 25.4 = 31.75

It is the mounting that differs. 31mm filters are unmounted with a very thin protective rim and hence have a slightly larger area. Both work in QSI cameras with internal wheels.

/per

[lensman57]

Have you considered the QSI683? With the wheel so close to the chip I understand that you can use 1.25" filters to about f2.8. Do just drop IKI a line to check, but I'm sure that's right.

Build quality of the QSI is utter top notch.

Hi Sara,

I did drop IK a line regarding the 683 or 660, with regret my problem is the finance at the moment as I placed an order for the WO Star 71 with IK. I think that a 383 is just about pushing it me. Will have to do some thinking.

Regards,

A.G

[davew]

The 8300 chip is right on the cusp of usability with 1.25 filters. Annoying in some ways, especially if you already have the filters !

There are in fact two camera makes that use 31mm unmounted filters " In body ", the QSI and the Moravian. I did some tests with my Moravian and the 1.25 filters are just about usable if you don't go too fast. The filter wheel will use 31mm and 1.25 because the hole in the wheel is about the same. The reason I tried a 1.25 is that no one made a 31mm IR pass but all my other filters are 31mm and do give a full clear aperture.

I also know for a fact that one or two others with the QSI are using 1.25. ( Moravian said in their bumf to use 31mm and you'd have to request a 1.25 ) I know the QSI will work reasonably well because I've used calibrated subs from a QSI 583 a few times using fast camera lenses. ( Stopped down in the case of the QSI )

With any other camera you'd have to use an external wheel. If you look around you'll see that they are 36mm for a few cameras. 36mm filters are way more than both the 1.25 and 31mm ( Which cost around the same as each other the last time I looked )

There was a thread somewhere that plotted a few attempts at 1.25 with an Atik I think. Can't really say that I remember the outcome because by then I'd bought my Moravian and that was three and a half years ago !

Have a look here at a few measurements of camera noise in 8300 cameras - http://blog.astrofotky.cz/pavelpech/?page_id=782  The difference is amazing !

Dave.