Colour fringing (1 Viewer)

Been digiscoping for a couple of months now
I am getting fringing on my pictures.. bright pinks and "sea green" colours, what are the best methods for me to reduce it...have a look at my gallery to see what I mean. My scope is an opticron classic which does not have ED glass. I want to keep working with the scope because I cant afford an ED one and the scope was bought for me by someone else (I would not want to offend them). The scope dopes work quite well and I have got some reasonable pictures with it. I have matched it with a 18x HDF eyepiece and use a cp4500.
If I get myself a 30x eyepiece could I reduce the fringing on the higher mag shots. I often find I'm zooming up to 4x on the Nikon (giving 72x mag). If it were on a 30x I could get 60x by zooming up to 3x Nikon. Asuuming the Opticron glass is better than the Nikon it might come out cleaner.
But am I being too ambitious with magnification? obviously for a nice pic often you want to fill the frame as much as possible, I always try to get as close as I can get (safely & consideratly). What level of magnifications do other people use on photos (wader & wildfowl shots can often be at distance).
Editing?- I've tried editing to reduce fringing, sometimes this can but other times it's impossible. The magic wand tool (on ACDsee) can be used to select areas then the saturation reduced on the clour section...or using the close and blur tools to belnd over the area.
Maybe my I start off editing a photo might not be the best? The way I usually edit a picture is to alter highlights and shadows for red, green, blue & luminescence to just below clipping. Then I go to auto exposure and adjust thios slider less of more until the colours and birghtness and contrast look right. Then I do an unsharp mask and save the picture. If the pictures looks okay thats all I do.
Do light conditions cause problems? recently the light has been low. Is fringing worse in bright or low light or the same? Its probably best for me to always have the light behind me if I can. Birds with strong contrasting plumage are probably the worst? I notice birds in cover or on ground get less than those with sky or water behind them.
Long question but thanks to anyone who can answer any of these questions.

Hi felthad,

What you have is called - Chromatic Aberration, it is caused by imperfections in the glass/plastic used in lenses. The best way to reduce it is to use the best quality lenses you can afford, in the case of digiscoping an ED scope! I have had some pictures with this on and you can reduce it in photoshop using a variety of methods. One I have used is to adjust the hue/saturation controls.

Hope this is of help, look up Chromatic Aberration via Google and see what you get.

Pete :~} :eat:

This is a quality of glass issue. I had it with my old Kowa 821M and the CP4500. Try to avoid bright backgrounds is the best way. For ducks on water look for low angled light or shady areas and into trees try to find a solid background (tree trunk ) or blue sky not white. For magnification 60x optical (combined) is about it with good optics so closer is always better when the conditions are not ideal.Hope this helps, Neil.

Thanks to sidrat & Neil. I think I must aim to reduce it in the origonl photo by choosing not to photo at bad angle/conditions. Over water (with reflections) and against bright sky are the worst. Might try and get a 30x eyepice see if that helps. While I'm inexperienced I think some of my settings didnt help, move my contrat to + instead of minus on cloudy days...try experimenting now that I'm more used to the camera. shooting against the sky will often make the subject dark (if a branch its sitting on swaying and the exposure target takes a reading form the sky..instead of the bird). I'll have to see if springtime light will give me better pictures because so far a lot of my trips out been overcast and dull. Editing only really seems poissible if the plumage colours and complexity are suitable.

felthad,

Use as low power as you possibly can: low power eyepieces + lowest camera zoom to just remove vignetting + getting as close to subject as possible. The CP4500 at 4x zoom is a recipe for soft images. And if you are seriously interested in digiscoping, I am afraid there is no way to bypass the advantages of an ED-scope. :t:

Ilkka

Thankyou Iporali..The origonal advice you gave when I was getting my kit together, really see what you mean now. Only solution for now is to take relatively closer up photos, try to get closer. Been thinking a more powerful lens might solve that much. Do enjoy digiscoping and am quite serious will hopefully get some ED glass when I can. Even with ED some of the magnification extremes might still have been too much (using >3x on the Nikon).

felthad - I hope I didn't sound too discouraging. Digiscoping is fun, but unfortunately it is not easy to get great images at typical birdwatching distances even with the ED/APO scopes. But yes, you certainly have got my point: low power & close distance are the way to go (20-30x eyepiece + 1-2x camera) - also with an ED scope. :t:

Best regards,

Ilkka

Hi Felthad - I have just mad a psot in the Opticron forum which is very relevant to your question. I hope no one minds me reposting it here for you.

I have just upgraded from an Opticron IS60 which I had bought 2 HDF eyepieces for to a GS665 ED.

I spent 2 months researching before I upgraded because I was concerned about wether there would be much of an improvement in practice. The cost of the upgrade was £450 for the 665 ED (body only) as opposed to the £100 the IS60 body cost and I really didnt want to throw away money that I dont have to spare.

Quick answer - the difference 'for me' is stunning, and I am thrilled I took the leap. I really wish I had done it first as now I am not sure what to do with the IS60 body!

Whats good and whats bad - a quick comparison -

IS60:
This is a very compact lightweight scope which is no effort to carry around. The optics are super at 20x and by eye appears very good at 32x (but I had not had the chance to look through anything better!).
I am into digiscoping and the 20x magnification photos are - well stunning really. But the 32x photos were poor. They were not sharp and suffered a lot of purple fringing.

GSED665:
I couldn't believe the difference optically. The image is so sharp its almost frightening at 22x (this scope alters the magnification slightly from the IS60). At 34x its is still stunning - no more soft wooly photos or purple fringing! - and to my eye, well I grin hugely everytime I look through it at this magnification now.
But - and there is always a but. The 665ED scope is far heavier - you know you are carrying it around. It is also slightly bigger - and because of its weight requires a sturdier - read heavier - tripod.

The expense was serious, but so was the image difference.
Now I wouldn't consider Opticron non ED glass unless I was using 20x magnification or less. (It appears many digiscopers only use a 10x eyepiece for this reason, but this is no good when the birds are a 100 meters away!)

But due to the more serious commitment of carrying it all, I have noticed I am a lot more choosy about when I go out birding (read that as less often).

Finally:
My birding photos - even at 34x are now very very good (sorry if that seems like I am blowing my own trumpet).

If you can afford it do it - buy ED. You really won't regret it. I had a job finding the cash, but wish I had done it first.

Basically - keep the magnification low and ensure your camera is line up properly central to your scope (yes this makes a big difference).

Best of luck - Adrian

Cheers Adrian read your reply. True an ED glass scope's gonna help solve the problem. I'm unemployed at the moment...loads of time for birding! (great) also doing voluntary surveys, guided walks ect to get experince to hopefully work in birds eventually. I would like to upgrade in the future (probably when I'm working again) and was intending to stick with Opticron brands. This will mean I can re-use the HDF eyepiece. Options would be the GS or simular. Or even go as far as a 100mm ES scope..would be really heavy but work even ok on those dreary winter wader photgraphing days. The tripod I use is heavy but very good...I coupled a manfrotto 144 with a sturdy manfrotto head. Carrying the stuff about for a day does make me muscles ache but I dont mind if I can take better photos.
Been thinking why the Nikon is soft focus if pushed above 3x mag..in addition to inceased colour fringing (which make edges less ditinct) theres the depth of field. At 4x the depth of field (through a scope) would be very low. Firstly this will make it difficult to find the focus point. Secondly although you may have focus on part of the bird the rest may be close or past the depth of field range ...so not as sharp.
For now I need to get close up (without disturbing) which I'm learning a tricks for now. Some times it pays to really take your time moving in. If its something like a wader/duck thats feeding they wont fly away unless they see you so there is no point rushing in care-less. For the perching ones the problem is they will move on soon...much more difficult. What I try and do is walk slowly watching and listening carefully. The idea is if I can see it before it does me then I can can prepare my camera before I get there. I can then approach in a way (that will hopefully!) keep them there a while. Sometimes Its a success and I'm chuffed other times I'm cursing under my breath- but that makes it a challenge. The main thing I'm interrested in is being ambitious and photoing a variety of birds doing what they do naturally. Dont want to just stick to ideal photos of the easy birds.

I try different ways of focusing depending on the situation. If I got time I focus the scope then attach the camera...this suited to birds that are going to stay put. If I'm walking through eg woodland I have the camera perminantly attached and everything ready. I use my binos to spot things then only focus though the camera if see something...much quicker seems to work (but correct me if this is wrong).
I use continuos shoot and hold it down if I want to take a series of shots...I make re-adjustments if it moves or sometimes to seek a sweeter focus. I'm asuming that the eye accepts a range of focuses but its still possible to fine tune it to the optimmum one if you can.
At the moment I'm not using a shutter release (my eagle eye one broke)...the tripods has seemed strong enough to not wobble if I press by hand-makes the whole process less fiddly and quicker. But I do use a slide viewer over the monitor if the lights from behind.
The number three way oif focussing I havent heard of but I can see why it might help you get an accurate focus- but would that mean the camera adjusts focus over the range of its zoom? I was always adjusting focus if I zoom up. I always start at the lowest zoo and start working my way from there.-I found this worked better than last position..easyier to locate your bird and helps prevent me over-magnifying.
Eyepieces- A low power one would be useful for real close ups. The current one is HDF18x on my scope still works well at close range down to a few meters but the top range where I can get reasonable photos I estimate is about 20 meters. A range of HDF eyepieces between 10 and 30x might be an isea for the future then I can transfer them to an upgraded body if I want to.
I also got an eagle eye lens to go directly on the coolpix-have not taken many phots with it but I tried it the other day and took good close range stuff and mcuh smaller and quicker to handle- so I might try to use it more in future.