Filter size, placement, and sensor size.

[Nugs]

Having saved hard for a few months, im looking to pick up a couple of filters (Baader neodymium and L-enhance or similar)

Currently using an Olympus DSLR, but soon investing in a 533mc ....... would i be OK with 1.25 filters regarding the sensor size, and would best placement in the imaging train be in the flattener or a filter drawer?

Scope is WO ZS 73ii.

TIA, Dave

[Richie092]

Hi Dave

I have the 533mc, great camera. I'm waiting for the 533mm to come out then plan to use it with 1.25" filters as I have them but I plan to get them as close as possible to the sensor.

try this calculator with your measurements and see what it says...

http://astronomy.tools/calculators/ccd_filter_size

Richie

 

 

 

[scotty38]

I am currently using 1.25" on a 294MC so on a 533 they will be absolutely fine but mine are pretty close to the sensor as I'm using a ZWO filterwheel. Obviously if you start putting them further away then you're going to need to use the tool as mentioned above.

[teoria_del_big_bang]

I would think a filter drawer placed as close to camera as possible would be the best option.
Of course yes use the tool mentioned above to confirm this, but I would be surprised if you could get away with 1.25"  in the flattener as more usually require 2" (but I do not know this for sure with your setup) but besides this you also then have the option to change filters easily and quickly and  without disturbing the angle of the rest of the optical train and so keep the FOV at the same angle.

Steve

[scotty38]

+1 to what Steve says, unless you plan to only ever have one filter please, please get a drawer or a filter wheel. You can thank me later 🤣🤣

[Nugs]

2 hours ago, Richie092 said:

Hi Dave

I have the 533mc, great camera. I'm waiting for the 533mm to come out then plan to use it with 1.25" filters as I have them but I plan to get them as close as possible to the sensor.

try this calculator with your measurements and see what it says...

http://astronomy.tools/calculators/ccd_filter_size

Richie

 

 

 

Cheers Richie,

A quick look on the calculator and it looks like i'm quids in and can go for 1.25"....... add on a filter drawer, and i'm still below cost of two 2" filters.

👍

[Nugs]

1 hour ago, teoria_del_big_bang said:

I would think a filter drawer placed as close to camera as possible would be the best option.
Of course yes use the tool mentioned above to confirm this, but I would be surprised if you could get away with 1.25"  in the flattener as more usually require 2" (but I do not know this for sure with your setup) but besides this you also then have the option to change filters easily and quickly and  without disturbing the angle of the rest of the optical train and so keep the FOV at the same angle.

Steve

 

1 hour ago, scotty38 said:

+1 to what Steve says, unless you plan to only ever have one filter please, please get a drawer or a filter wheel. You can thank me later 🤣🤣

Thanks both,

Definitely going for the filter drawer, and the calculator says i'm fine with 1.25", especially when i move over to the 355mc sensor. 👌

[Planitair]

Not sure how you can get a 2" filter near to the sensor on the 533 using the available spacers for back focus. 86mm is nearest I can get it, seems to work ok, would be glad to get some advice on this. I use Sharpcap high Gain ( 300 +) with lots & lots of 30 sec subs.

 

[Simon Pepper]

On 15/02/2022 at 16:21, scotty38 said:

I am currently using 1.25" on a 294MC so on a 533 they will be absolutely fine but mine are pretty close to the sensor as I'm using a ZWO filterwheel. Obviously if you start putting them further away then you're going to need to use the tool as mentioned above.

Hi scotty

jus to confirm do you have any vignette with the 1.25 and the 294? I am thinking about getting the same…

THANKS 

 

[scotty38]

14 hours ago, Simon Pepper said:

Hi scotty

jus to confirm do you have any vignette with the 1.25 and the 294? I am thinking about getting the same…

THANKS 

 

I don't have that camera now as I swapped to a mono setup although I went for a QHY294m and 36mm filters just to future proof an upgrade to a 268.

Having said that I think there was a small vignette but nothing that flats didn't fix, I certainly never noticed it as being anything obvious

[AstroMuni]

On 15/02/2022 at 15:43, Nugs said:

but soon investing in a 533mc ....... would i be OK with 1.25 filters regarding the sensor size,

If its just one filter then it fits neatly next to the ASI533mc Pro sensor. The camera comes with the necessary adapter (T2 to 1.25") for that and thats what I have used to attach the UV/IR cut filter. But the uncooled version doesnt come with these, is my understanding. And if you need to change filters in the middle of an imaging session then you would definitely need a drawer or wheel.