Lack of contrast sample (1 Viewer)

Roy C · Mar 8, 2013

This is just an average snap that I took recently but is a good example of the lack of contrast you can get 'straight out of the Camera' with the SW80ED (at least with my set-up). This is a good example as the black point is way out but for any novice's who may be disillusioned by this pic #2 shows what can be done by just a 20 second correction of the levels.
I am not quite sure why some pics are worst than others with regards to the lack of contrast (probably a bit more severe when using a tc) . also not sure what causes this in the beginning but either way it is easy enough to correct although I suspect this must cause some loss of the dynamic range.
What are other folks take on this?

7D + 1.4x tc + SW80ED

Pic 1 : Straight out of camera (just converted from RAW and resized for web)
Pic 2 : Levels corrected (especially the black point - takes less than a minute)
Pic 3 : The finished shot with a bit of processing (this is just a quick and cheerful edit!)

JGobeil · Mar 8, 2013

It looks like fogging to me. I've experienced thas this winter when taking the scope outside in cold temperature and taking pictures immediately. My pictures looked very much like yours and correcting levels in PS helped but the pictures were still flawed.

cango · Mar 8, 2013

JGobeil said:
It looks like fogging to me. I've experienced thas this winter when taking the scope outside in cold temperature and taking pictures immediately. My pictures looked very much like yours and correcting levels in PS helped but the pictures were still flawed.

agree. fogging has caused me trouble a (very) few times.

Roy - have you flocked (additional) your tube inside? That helps with the contrast quite a bit. (not that your image here has to do with bad/non flocking, but - i guess - fogging or so)

Paul Corfield · Mar 8, 2013

I'd agree with Jules and Cango, your objective lens had probably fogged up. I keep my lens cell only screwed up hand tight so that I can take it off quickly and wipe it off using a cloth. I use a proper lens cloth, it's quite a big one at maybe 25cm square. Once the scope has had time to cool down to the surrounding temperature it shouldn't fog up again.

There are anti fogging coatings available for camera lenses that would probably be fine to use on the scope too. Might be worth looking into.

Paul.

Roy C · Mar 8, 2013

Its certainly not fogging guys, every single shot I have ever taken with the astroscope has been like this to some degree - The black point always needs rectifying regardless of temperature or anything else. lovely warm day today in North Devon so been out for a few hours, all the shots need rectifying as far as the black point goes. Like I say it is no great shake as it takes seconds to rectify.

I have not flocked anything in my set-up but it looks to me as if some stray light is getting in somewhere.

JGobeil · Mar 8, 2013

The histogram is completely to the right, exactly like my fogged pictures. Could it be that your lens is clouded permanently ? With some kind of white dust, fungus or something else?

JvdM · Mar 8, 2013

Hi Roy

Could be that your lens hood/dew shield is too small? or not fully extended. This tends to happen when the sun is just outside the FoV. You have to flock the dew shield as well.

Try some shots towards the sun and some away from the sun and see how it affects contrast.

Jaco

cango · Mar 8, 2013

Roy C said:
Its certainly not fogging guys, every single shot I have ever taken with the astroscope has been like this to some degree - The black point always needs rectifying regardless of temperature or anything else. lovely warm day today in North Devon so been out for a few hours, all the shots need rectifying as far as the black point goes. Like I say it is no great shake as it takes seconds to rectify.

I have not flocked anything in my set-up but it looks to me as if some stray light is getting in somewhere.

In that case it has to be some stray light getting in (the way). That's not how it's supposed to be. I have never needed to work with the black point, even before flocking it.

No wonder you haven't been as sold to the lens as many of us have

Roy C · Mar 8, 2013

JGobeil said:
The histogram is completely to the right, exactly like my fogged pictures. Could it be that your lens is clouded permanently ? With some kind of white dust, fungus or something else?

Shooting to the right (ETTR) without clipping the whites of course is exactly what I want Jules - with 80% of the tones being in the brightest 20% of the histogram then the very last thing I want to do is to underexpose and then have to push up in processing as this mean less dynamic range and more noise in the shadows.
I would much sooner push the blacks than the whites that's for sure.

Roy C · Mar 8, 2013

JvdM said:
Hi Roy

Could be that your lens hood/dew shield is too small? or not fully extended. This tends to happen when the sun is just outside the FoV. You have to flock the dew shield as well.

Try some shots towards the sun and some away from the sun and see how it affects contrast.

Jaco

Jaco, the hood is a fixed item on the SW80ED - as previously stated I have not flocked anything.

Roy C · Mar 8, 2013

I suspect what is causing this aside from not flocking is the fact that I shoot to the right (ETTR) which means that the white point is always going to be correct but the black point will often be out. If I were to meter for the mid point I suspect both the black and white points would need a bit of 'levelling' due to the lens producing relatively low contrast anyway.

JGobeil · Mar 8, 2013

Roy,

Have you checked for white dust or fungus inside the lens or TC or on the sensor ?

Roy C · Mar 8, 2013

All joking apart guys I have always thought that my images stood up fairly well with the majority of shots I see on the astroscope forum here on BirdForum. Maybe I am missing something and all my shots are poor compared to you guys!.
Attached are typical example of what I am getting with a 1.4x tc attached - are they all that bad?. (Everyone was shot to the right so the black point needed levelling)

Roy C · Mar 8, 2013

JGobeil said:
Roy,

Have you checked for white dust or fungus inside the lens or TC or on the sensor ?

Yep, everything is clean as a whistle Jules.

Hobbes2 · Mar 8, 2013

For what it's worth, every digiscoped shot that I have seen, straight out of camera, always lacks significant contrast. I assumed it was something to do with the distances involved and stray light along that distance. Many people don't realise that their digiscoped shots can be signficiantly improved by either upping the contrast or sorting out the levels.

Your experience, Roy, seems to be consistent with what I've seen from digiscoped images, including the fact that your shots contain all the potential, it's just a case of having the skill to realise it through Photoshop etc.

Hope that helps
Hobbes

cango · Mar 8, 2013

Roy C said:
All joking apart guys I have always thought that my images stood up fairly well with the majority of shots I see on the astroscope forum here on BirdForum. Maybe I am missing something and all my shots are poor compared to you guys!.
Attached are typical example of what I am getting with a 1.4x tc attached - are they all that bad?. (Everyone was shot to the right so the black point needed levelling)

Absolutedly not - your shots are not bad at all - please do not interpret it that way. All I was saying was that YOU seemed to think (compared to your canon lenses) the scope was not getting you waht you aimed for - and maybe the lack of contrast/ light spill/whatever/ was what caused it.

One thing to consider is the way we prefer to shoot. You seem to shoot many birds from long distances, and that as we know is challenging. I myself prefer to get as close as I can (and don't have wetlands/marshes around me to be tempted to shoot at longer distances).

Love the raven (?) - very detailed.

Roy C · Mar 8, 2013

Hobbes2 said:
For what it's worth, every digiscoped shot that I have seen, straight out of camera, always lacks significant contrast. I assumed it was something to do with the distances involved and stray light along that distance. Many people don't realise that their digiscoped shots can be signficiantly improved by either upping the contrast or sorting out the levels.

Your experience, Roy, seems to be consistent with what I've seen from digiscoped images, including the fact that your shots contain all the potential, it's just a case of having the skill to realise it through Photoshop etc.

Hope that helps
Hobbes

Thanks for that 'Hobbes' I was beginning to think it was just me B

.

If everyone else is getting a lot more contrast than me than without being unkind I am not seeing it on the images posted! Although maybe it is my tired old eyes lol (over 50 years working in a factory does not help!).

Roy C · Mar 8, 2013

cango said:
Absolutedly not - your shots are not bad at all - please do not interpret it that way. All I was saying was that YOU seemed to think (compared to your canon lenses) the scope was not getting you waht you aimed for - and maybe the lack of contrast/ light spill/whatever/ was what caused it.

One thing to consider is the way we prefer to shoot. You seem to shoot many birds from long distances, and that as we know is challenging. I myself prefer to get as close as I can (and don't have wetlands/marshes around me to be tempted to shoot at longer distances).

Love the raven (?) - very detailed.

Hi Cango,
After owning some of the very best telephoto lenses ever made (e.g. the Canon 300/2.8 IS for one) I am still amazed at the IQ to be had from these cheap astroscopes, especially when used with a tc considering it is a very slow f7.5 to begin with (f10 ish with a 1.4x tc).
There is no way I would ever expect it to be up to the best DSLR lenses and lack of contrast is a sure way of sorting out the wheat from the chaff when it comes to telephoto lenses.

You are right about me only shooting from long distances but this is the only reason I have the SW80. If I could get near enough not to need 840mm (plus big crops) I would be shooting a normal SLR lens at 400-500mm. Besides which I still have three or four SLR lenses for closer stuff.

I have taken a few close shots with the astroscope and to be honest I have been disappointed (unlike the distant shots which are fine). I think the main reason is the fixed aperture which some what limits the DOF for close-up (but is fine for distant stuff where you want to isolate the subject from the background).

I am certainly not complaining about the lack of contrast but after hearing about some folks who have all but given up on astroscoping because of it I posted this just to show how quick and easy it is to somewhat overcome this poor contrast.

P.S. attached are a few close-ups I took a few days ago, I was shooting with a 1.4x tc from no more than 15 foot. Although they are not bad I would have expected a lot better if I were using an expensive Canon 'L' lens. Not that I am complaining seeing they were taken with a sub £300 'lens'

Hobbes2 · Mar 8, 2013

Roy C said:
Thanks for that 'Hobbes' I was beginning to think it was just me B .

If everyone else is getting a lot more contrast than me than without being unkind I am not seeing it on the images posted! Although maybe it is my tired old eyes lol (over 50 years working in a factory does not help!).

Nah, definitely not just you, Roy

. As I say, I have seen a good number of digiscoped images from a number of birders (different scopes/cameras etc) and all of them initially look "disappointing" (washed out etc). It's not until you realise that with a simple application of contrast or correction of levels, the image is completely transformed.

Personally, I have been very impressed with the results you've been getting with your astrocoping kit.
All the best
Hobbes

Roy C · Mar 8, 2013

Hobbes2 said:
Nah, definitely not just you, Roy . As I say, I have seen a good number of digiscoped images from a number of birders (different scopes/cameras etc) and all of them initially look "disappointing" (washed out etc). It's not until you realise that with a simple application of contrast or correction of levels, the image is completely transformed.

Personally, I have been very impressed with the results you've been getting with your astrocoping kit.
All the best
Hobbes

Thanks 'Hobbes', Yep, 'washed out' is what I have heard from a few folks who were disillusioned with astroscoping and this post was just to show how easy it is to rectify.
Still it seems to have made for an active thread anyway!

Lack of contrast sample (1 Viewer)

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