SharpCap Forums

Hi Brian,
I am 4.5 - 5 depending on direction although it also depends whether the neighbour's cat is turning on the security lights that everyone feels the need to install nowadays.

Cheers
Nick

I just saw an error i made a few posts ago.

I said: I increased the gain twice.

It should say: I increased exposure twice.

Gain stayed at 110 the whole night. My error.

I'm sure you caught that mistake but just want to make sure.

Frank

Brian,

Your question...I did a search on SpaceCat and found f/4.9. Is that not correct?

That is correct. I believe it is the exact same unit as RedCat 51. Just different color scheme.

Frank

Frank,

Something else I noticed, take a look at Dave's M33 that he posted last night:
viewtopic.php?t=9257

The red pinpoint features are Ha. This is one of the wavelength's that your nebula filter passes. The other wavelength the filter passes is OIII. Now, my experience tells me that OIII is most often found in nebulae, not necessarily galaxies. Now, in Dave's image the fainter arms of M33 were captured in RGB. So what I'm getting at, last night when your image was building in LIveStack you were likely only seeing the pinpoint red structures of the galaxy, probably nothing more than that. Maybe you weren't expecting that so you gave up on it.

Brian

Hi Nick,

AH, Bortle 4.5 - 5. Rural skies. That explains your longer exposures. I think that Frank is in or near a town center.

Thanks,
Brian

Interesting.
I did notice a little more pointed red areas like stars towards the center. The spiral arms were very faint.

oopfan wrote: Wed Jan 07, 2026 11:02 pm Hi Nick,

AH, Bortle 4.5 - 5. Rural skies. That explains your longer exposures. I think that Frank is in or near a town center.

Thanks,
Brian

Scrap that have not checked for 3 years and we have had a lot of building in the area now appear to be at Bortle 5 -6 or 6.5 - 7.5 depending on where I look.

Frank,

So I think you are better off using the IR/Cut filter for M33, just wait for the Moon to be less of a factor. Bring out the nebula filter when you are going for emission nebulae, not reflection nebulae. M45 is a reflection nebula, for example. If uncertain about the type of nebula, Wikipedia is a good source of information, or you could ask here.

Also, if the Moon is out and you have a clear night, shoot the Moon! Dave does that very effectively and he's won multiple awards at AstroBin and magazines.

Brian

Hi Frank,

I don't know how dark your sky is to the east-northeast but this is a perfect time of year for M81/M82:
https://commons.wikimedia.org/wiki/File ... laxies.jpg

It's available in the evening for several hours since it is nearly circumpolar. Use IR/Cut although M82 looks great in Ha too. In a single frame you'll definitely capture the core with a hint of spiral arms, but you have to give it time to build up. How long is long enough? My experience with my refractor (f/5.9) and CCD (large pixels) at Bortle 5.3, any galaxy or nebula needs 10 hours to come out really nicely. Your results may vary.

Another good one, although smaller is M109:
https://en.wikipedia.org/wiki/Messier_1 ... field).jpg

And if you want a challenge similar to M33, is M101:
https://en.wikipedia.org/wiki/Pinwheel_ ... 06-10a.jpg

Don't be fooled by that Hubble image. It is large and has low surface brightness. You'll capture the core and a whiff of the arms but it's going to take a lot of integration time.

You are entering prime "galaxy season". There are a lot of targets to choose from. However, say goodbye to nebulae until about April/May. Nothing really interesting this time of year except the Jellyfish Nebula:
https://en.wikipedia.org/wiki/IC_443#/m ... yright.jpg
It would be a great target for your nebula filter.

Of course there are always star clusters, but they get no love from most astrophotographers

By the way, emission nebulae are very popular with astrophotographers who have significant light pollution. Emission nebulae emit Ha, OIII, and SII but almost always Ha is the strongest (with the exception of Planetary Nebulae which are strong in OIII.) Chuck Ayoub of "Chuck's Astrophotography" lives in the heart of Detroit, Michigan. His photos make it to publications and Wikipedia. Here's one:
https://en.wikipedia.org/wiki/NGC_281#/ ... GC_281.jpg

You may find that your nebula filter (Ha + OIII) is a godsend.

Brian

If going Ha + OIII then it might be worth looking at the dual filter sets so Ha + OIII and OIII + SII so that if you image with both so for say 2.5 hrs each you would have 2.5hrs of Ha and SII and 5hrs of OIII. Askar do paired sets depending on the amount you want to spend they do the C1 + C2 which is the cheapest and widest band pass or the D1 + D2 which is tighter bandpass or the E1 + E2 which are 3nm. Antlia also do them in various band passes under the ALP-T range which I am looking at in 3nm in the off season ready for September as currently spending money on my other addiction which is my Rally Sim motion Rig too many hobbies not enough cash .

Once you have integrations from both you can use something like DBExtract in Pixinsight to split the two integrations into three images one solely Ha one solely OII and one SII so you can combine them in the Hubble pallet or however else you wish.

Cheers
Nick