How do you apply flat fields

[Striker]

Hi All,

I did my first flat field shots early this morning....now I need to know hot to apply them to the images I have taken..

I had a quick look at Iris and are totaly confused...is their an easy way to apply flats.

What program can I use and is there any easy tutorials.

[[1ponders]]

Hi Tony. Yep Iris can be like that. If you haven't already download Jim Solomons Cookbook http://home.comcast.net/~jimc8ngt/articles/cookbook/ and see how you go. It helps if you can understand the processes he uses, but its not essential. Just follow the steps he outlines.

CS

[beren]

Tony im surprised you havent got ImagesPlus , as far as i understand it the program does everything in auto mode for you , might be worthwhile downloading the demo and see what you think

[Striker]

Thanks Stuart.....Just downloaded it.....very very easy...just what I needed....too bad the demo has a cross over all images...

May have to buy it...dam

[RB]

Images Plus- well worth it.
Great features.

:drink:

[Robby]

Mathematically flat field processing is a "divide". You can invert your flats and then multiply with the image in photoshop to acheive the same result. Although using IP is much easier!
Cheers

[Striker]

Your not wrong it's easy...I just spent about and hour reading up on Iris on how to do it being completely confused, talk about a long and technical process....and it's only 2 clicks on Images plus.

[h0ughy]

How much and where do i get it? :)

[Striker]

Huffy,

Do you really want to know.

http://www.mlunsold.com/

$200 USD = approx $270AUD....you will be happy to know that includes postage....lol

[h0ughy]

:scared: :scared: :sad: thats almost too dear!

EDit it doesn't support my Pentax :confuse3:

[asimov]

What about in registax? It has the facilities for it. I have'nt tried it yet though.

[rumples riot]

Seems like a lot of cash, what other features are useful in Imageplus? I know a lot of guys in the states are using it. Especially the CCD guys.

[Striker]

Yeah I agree Paul.....even with the Free Demo I cant really use it as it puts a black cross over the image.....I wouldn't purchase it just for doing Flats....but it makes it very easy.....nothing comes close for ease of use yet...but I am still looking

Cant help you regarding features....I was just happy to see it do flats.

[beren]

Heres the page for the features http://www.mlunsold.com/ , with processing being a major factor in imaging nowadays and the money put into the purchase of a DSLR buying a user friendly program like IP is a worthy investment i reckon , if i had the computing power i would have it in a heartbeat

[rumples riot]

hmmm, looks good Stuart, I can run my D70 straight into it and it helps focus and all sorts of Nikon support. Might have to consider this at some stage.

[beren]

Only thing Paul the nikon has a infa red shutter release , the cable OPT or hap griffin sells that suits the D70 is expensive but it would save us being slaves to a stopwatch .Even though the program comes with video tutorials i brought a how to handbook for the program and it looks great even from my rookie understanding

[Striker]

Paul,

Have you looked at Chris's DSLR Focus software....I am using it atm.....I just ordered some cables from shoestring so I can control everything including longer exposures over 30 seconds from my PC using Chris's software.

[beren]

If Paul has Nikon capture you can use Chris program although for shutter release control you still need the infa red cable hap griffin or OPT sell

[RB]

Where did you find the handbook beren?
How much is it?

Cheers

[beren]

From OPT Andrew http://www.optcorp.com/ProductList.aspx?uid=105-258-259-261 theres one aimed for canon DSLRS and the one i have is for the nikon d70 .The main purpose of the book is to get you going and producing results quickly with Images plus , i think the cost was around 30 au , if anyone is interested in loaning it i would be happy to pass it around.

Noticed on the OPT site that Maxim DL has a DSLR software program too http://www.optcorp.com/product.aspx?pid=105-243-244-245-7526

[h0ughy]

I thought I was totally left out of this but have found this http://www.dpreview.com/news/0403/04031401pentaxistdremote.asp I will give it a go and see what, or how it will work for astrophotography. At least it is something for Pentax Owners, it seems the popularity of the Canon and Nikon cameras has won out and programmers have not included many other cameras in their software. This is the case for Image Plus, and DSLR software.

[cventer]

Here is a link to a free Digital Astro cookbook that discusses darks, flats etc.. and the use of the free software IRIS to process your images.

http://home.comcast.net/~jimc8ngt/articles/cookbook/index.html

Best Regards
Chris

[Striker]

I have read Jim's soloman cookbook...well tried too...At this stage of my astrophotography I found it to be very difficult to understand....maybe I am just reading into it too much....I would like to think what other feal about this Iris process regarding doing flats.

[seeker372011]

Tony:

I have been following Jim Solomon's recipe every single time since I started using IRIS and it works fine..

couple of cautions...in the new version of IRIS kappa sigma stacking works (in his cookbook Jim talks of a bug, but that I think has since been fixed)

also in general I like the add_norm command rather than straight add, it seems to work better

and savepsd2 seems to work well when you finally save to photoshop (instead of that complex process Jim describes to save to Photoshop).

Conceptually processing in IRIS is quite straightforward:


convert RAW to a Pic file
Apply flat field and subtract darks
convert to 48 bit
register
stack
set black point and adjust colour balance
stretch-using asinh command-I love this command
save to photoshop


There's heaps of other commands for power users but the basic set needed to do the steps above are pretty much what I need 95 % of the time

give it a go, I think you'll be pleasantly surprised at what it can do


I need to add that the procedure Jim describes to take flat fields did not work for me for a flat without filter..worked Ok when I had a filter in the optical train..not sure why need some experimentation to find out

seriously think a light box a la Eddie T is the way to go (See Eddie's fine article if you have not already)