DIY T-Shirt Flat Filter and Embroidery Hoop

[Doug]

I created a T-Shirt Flat Filter for my EON120 Telescope today. It was an easy project. I purchased $1.29 Embroidery hoop (6") and took an old t-shirt. I used three layers of the t-shirt to avoid patterns from the fabric. I laid the the layers across the inner hoop (Cris-cross fabric patterns on your layers). Then on a flat surface slide the outer hoop over the layers. I then cut off the excess T-Shirt with scissors.

This should help with Dawn flats. I always get an unwanted stars early in the morning and the T-Shirt flat should defuse the stars.





I'll test it on my next outing!

Doug

[Djennings]

Hey Doug,

Looks promising and I plan to do the same. Please let us know how this works out for you.

Thanks,
David

[Doug]

David,

Works great! I use to have problems with morning stars in my flats. The T-Shirt flat eliminates all stars and gives a nice uniform pattern. I highly recommend T-Shirt flats.

Doug

[Bill]

Great idea with the hoop. You are probably aware dawn flats can be taken without any tracking or guiding which is self explanatory on a longer exposed flat. Also, as with most flats with any fabric or patterned material, a 1 or 2 pixel blur can be of great service.

On a bit of side note, I am finding the color white is not always so white. It can mess with blues and yellows depending. I have wondered if anyone has tried a neutral grey for a flat? Photographers can use a particular color downloaded or purchased for establishing custom white balance settings. Would that be appropriate to try you think?

good, luck Bill

[Doug]

Bill,

Flats influence the color of your image as you noted. One of my first images I took was using a fluorescent bulb flat...it had a slight blue tint and my image reflected the results. if I knew more about colors and took the time to experiment, I'll bet colorizing your flats would make a difference. I created a new light box from LEDs...I need to post my build here. The LED flat box works better than the T-Shirt flats.

Doug

[Bill]

I prefer the LED box I have as well. It allows some flexibility if you wish to change your setup during a session among other things. I use flat sheen artist paper for the final "lens" and will try to experiment a little with different "whites".

Looking forward to seeing how you have yours built.

For the 12" tube of the RC I cut the top 4" off a 5 gal. bucket and utilized the snap-on lid to mount the led's, layered diffuser type material and a couple layers of paper. A few pieces of foam around the end for a tight connection to the scope tube and done. A rheostat, etc. but that is about it. The flat produced is flat but I'm still concerned about color loss.

Talk with you later,
Bill