"fast" lenses?

[mikeklensch]

Greetings all.

I'm new to this wonderful website and forum, and am looking forward to getting educated from the wealth of knowledge to be found here.

I'm interested in getting my feet wet with large format... either 4x5 or 6x12 panos using large format lenses (photoman cameras). I love doing night imaging, and I specilize in aurora photography. I know that large format lenses are slow compared to 35mm and medium format, and I need the fastest lenses I can find (without having to go into debt). Since I really wouldn't require either a shutter, camera movements or mulit-coatings, I was wondering about barrel lenses, and if there are any fast, wide angle ones out there on the cheap. And I was also wondering how usable they might be wide open... or if that would just greatly compromise image quality, (I'm especially concerned about coma with stars). So any advice/experiences you all might have would be greatly appreciated.

Many thanks,
Mike Klensch

 

[JG Motamedi]

If you will be using the Photoman you should be aware that many of the fast lenses will not fit on it.

That said, the fastest sharpest lens you will find is a Schneider 150/2.8 Xenotar. A tad slower but perhaps sharper are the Zeiss 135/3.5 Planar and Schneider 135/3.5 Xenotar. No problem with coma on these lenses.

For cheap? The Dallmeyer 8" f2.9 Pentac was made by the thousands for the British Air-ministry. Not very sharp but affordable. Coma will probably be a problem with the Pentac. Another lens which may work is the Kodak 7" f2.5 Aero-Ektar. I really dislike these lenses, but others swear by them. Since these were built for aerial survey work they should be well designed for what you want, however my two samples both showed serious coma. Another problem with these lenses is that they have a nasty brown stain in the glass which will need to be "bleached" with UV light.

There are of course other, mostly older, speed lenses available (f3.5 Xenars or Tessars, f2.7 Tessars and Biotessars, and a variety of odd British triplets), but these tend to be either dull open wide and/or loaded with coma (read: the swirly "artistic" bokeh).

good luck.

 

[Claire Senft]

What makes you think that the high lens speed will be more beneficial than a good tripod?

 

[JBrunner]

You may already have sumrised this, but with larger formats, you can use a faster film with much less penalty. The lens advice offered is very good, but if you can find a way get what you are after with a 4-5.6 your selection of affordable high quality lenses will multiply exponentially.

 

[mikeklensch]

What makes you think that the high lens speed will be more beneficial than a good tripod?

Thanks for pointing that out Claire...

I should have explained better what I was after. I try to get night images where the backround stars remain as "points", rather than "trails". So this limits my exposure time. I have done 4 hour startrail exposures, and, obviously, lens speed is not an issue here. But for most of my aurora photography, my exposures average between 10 to 30 seconds. So with this "short" exposure time, I really need the lens speed.

Thanks,
Mike Klensch

 

[Dan Fromm]

Mike, as others have told you, there are very few fast lenses that cover 4x5 or even 6x12. If cost is no object and you're willing to wait for one to turn up, you might look for a 6" (or 150 mm, after Dallmeyer went metric)/1.9 Dallmeyer Super Six. You just missed and I was outbid on a 200/1.9 Boyer Saphir on eBay.fr; yes, I know, longer than you want.

Good and inexpensive and fast don't go with formats larger than nominal 6x6. Good and inexpensive and wide don't go with formats larger than nominal 6x6.
Good and inexpensive and fast don't go with wide angle lenses in any format.

If you need wider than normal, your best option might be 35 mm. For fast normal, perhaps 6x6.

Cheers,

Dan

 

[mikeklensch]

Thanks everyone for the advice and information.

I thought that the combinations I was looking for (fast, wide and inexpensive) was probably asking for too much. But I just wanted to make sure I wasn't missing something due to my lacking large format knowledge. I suppose I guessed right. I think the largest format I can reasonably use and still have the attributes I need is 645 and 6x6. My Mamiya 645 lenses are 2.8 and resonably sharp wide open. I'll have to keep the large format equipment for daylight use or long exposure night use.

Many thanks again for the replies and information!

Mike

 

[Claire Senft]

Is the mechanism which can be affixed to a tripod that will compensate for the earth's movement relative to the stars to expensive to consider?

 

[mikeklensch]

Is the mechanism which can be affixed to a tripod that will compensate for the earth's movement relative to the stars to expensive to consider?

Hi Claire,

Actually "equatorial mounts" are are not too expensive (and I already have one), and I also have a "barn-door tracker" that I custom made myself. But if you're including the landscape as part of the composition, (like I normally do), they don't help your efforts, since the movement of the camera (attached to the mount), will blur the landscape. This would only be useful for compositions of just the sky which is something I don't often do.

I've also considered (but haven't yet tried), doing a double exposure of exactly the same composition over the course of two nights... where you would do your first exposure for say 25 seconds, close the shutter, and then leave the camera. Then return to the camera the next night and take the second 25 second exposure exactly 4 minutes earlier (on the clock) from when you took the previous night's exposure (to compensate for earth's precession...thereby ensuring the exact same location of the stars). The only problem with this method is that if you're trying to capture an aurora (the way I do), this does you no good since the aurora is dynamic and will be done and gone. Still, it would make for a really good photo with lots of star detail. I'll have to try it some day in a location where I feel comfortable leaving my gear and not having to worry about a curious moose knocking it over

Thanks,
Mike

 

[Harrigan]

Good and inexpensive and fast don't go with wide angle lenses in any format.



I suggest the Ross 5 inch wide angle express f4 might fit all the above. It's fast for a wide angle and about as inexpensive as you can get. I don't know how good it is but Ross makes quality optics so I assume its a good lens.

 

[jovo]

I've also considered (but haven't yet tried), doing a double exposure of exactly the same composition over the course of two nights...

Well....bingo! Combination printing is an old and venerable practice continued to this day by Bruce Barnbaum among several prominent photographers. Especially considering the dark prints you'll be making, combining a sky print with a landscape of the same area should not be difficult. You wouldn't have to time anything except the exposure of each subject. Blending the two in the darkroom is just a matter of masking each part individually in successive exposures.

 

[mikeklensch]

Well....bingo! Combination printing is an old and venerable practice continued to this day by Bruce Barnbaum among several prominent photographers. Especially considering the dark prints you'll be making, combining a sky print with a landscape of the same area should not be difficult. You wouldn't have to time anything except the exposure of each subject. Blending the two in the darkroom is just a matter of masking each part individually in successive exposures.

Thanks John... but that still doesn't get me my first (and most critical exposure) of the aurora. And the aurora is usually "touching" the landscape... not just directly overhead in the sky. So I would still need to shoot the landscape with the sky/aurora in at least one of the exposures... and the lens has to be fast enough to record that exposure in less than 30 seconds. Sigh... just no easy answer in LF... but the combination printing would be great in another application!

Mike

 

[mikeklensch]

Good and inexpensive and fast don't go with wide angle lenses in any format.



I suggest the Ross 5 inch wide angle express f4 might fit all the above. It's fast for a wide angle and about as inexpensive as you can get. I don't know how good it is but Ross makes quality optics so I assume its a good lens.

Thanks Harrigan... I'll look into it!

Mike

 

[Dan Fromm]

Good and inexpensive and fast don't go with wide angle lenses in any format.



I suggest the Ross 5 inch wide angle express f4 might fit all the above. It's fast for a wide angle and about as inexpensive as you can get. I don't know how good it is but Ross makes quality optics so I assume its a good lens.

Nearly all of the cheap ones, ex-Air Ministry, are uncoated. I have one, it is flare champion of the universe. Never seen anything like it. And its pretty clean.

Cheers,

Dan

 

[JBrunner]

Thanks John... but that still doesn't get me my first (and most critical exposure) of the aurora. And the aurora is usually "touching" the landscape... not just directly overhead in the sky. So I would still need to shoot the landscape with the sky/aurora in at least one of the exposures... and the lens has to be fast enough to record that exposure in less than 30 seconds. Sigh... just no easy answer in LF... but the combination printing would be great in another application!

Mike

I'm no astrophotographer, so correct me if I'm wrong, but wouldn't you have more on the order of 12 minutes or so before movement would become apparent with a 90mm lens? Or does the 30 second figure have to do with the aurora?

 

[David H. Bebbington]

Greetings all.

I'm new to this wonderful website and forum, and am looking forward to getting educated from the wealth of knowledge to be found here.

I'm interested in getting my feet wet with large format... either 4x5 or 6x12 panos using large format lenses (photoman cameras). I love doing night imaging, and I specilize in aurora photography. I know that large format lenses are slow compared to 35mm and medium format, and I need the fastest lenses I can find (without having to go into debt). Since I really wouldn't require either a shutter, camera movements or mulit-coatings, I was wondering about barrel lenses, and if there are any fast, wide angle ones out there on the cheap. And I was also wondering how usable they might be wide open... or if that would just greatly compromise image quality, (I'm especially concerned about coma with stars). So any advice/experiences you all might have would be greatly appreciated.

Many thanks,
Mike Klensch

Welcome to APUG! All I can tell you about this subject is that I have a 6.5 inch f2.9 Ross Xpress barrel lens which delivers the image quality that I would expect of a good uncoated lens and seems to cover 4x5" quite well (although I've only used it in the studio, not at infinity). Not a very common lens, though!

Regards,

David

 

[mikeklensch]

I'm no astrophotographer, so correct me if I'm wrong, but wouldn't you have more on the order of 12 minutes or so before movement would become apparent with a 90mm lens? Or does the 30 second figure have to do with the aurora?

No... at 12 minutes, you would have very significant trailing. The amount of time you can expose is dependent on lens focal length (as you already deduced), but it's pretty short. The old formula for 35mm equipment (which until now, I had mostly used for astro-work) is 600, divided by the focal length, will give you the amount of time (in seconds) you can expose before stars stop looking like points, and start to noticibly tail. So for a 50mm normal lens (in the 35mm world), this would yield 12 seconds. So, this would be the same for a 150mm large format lens. For a 90mm large format lens, you would have about 20 seconds of exposure before you would notice trailing... could maybe push it to 25 seconds.

My personal experience shows this formular to be pretty darn accurate. Now there will be some variability depending on your latitude, and what part of the sky you're pointed at (the sky will "move" less when pointed north and more when pointed east and west), and because I'm at 60 degrees N. latitude, I can do a bit longer exposures than someone at the equator.

In addition, the aurora can really rip across the sky as well. So, just as with running water, the aurora will blur, and you'll loose all of the detail and definition if you expose too long... heck, sometimes 10 seconds is too long if the aurora is really moving.

Hope that helps,

Mike

 

[mikeklensch]

Welcome to APUG! All I can tell you about this subject is that I have a 6.5 inch f2.9 Ross Xpress barrel lens which delivers the image quality that I would expect of a good uncoated lens and seems to cover 4x5" quite well (although I've only used it in the studio, not at infinity). Not a very common lens, though!

Regards,

David

Thank you David for the welcome and the advice. I'll keep my eyes open for that lens and see if it's a viable option. It would still be a bit long for my application, but I think it would be fast enough.

Mike

 

[JBrunner]

No... at 12 minutes, you would have very significant trailing. The amount of time you can expose is dependent on lens focal length (as you already deduced), but it's pretty short. The old formula for 35mm equipment (which until now, I had mostly used for astro-work) is 600, divided by the focal length, will give you the amount of time (in seconds) you can expose before stars stop looking like points, and start to noticibly tail. So for a 50mm normal lens (in the 35mm world), this would yield 12 seconds. So, this would be the same for a 150mm large format lens. For a 90mm large format lens, you would have about 20 seconds of exposure before you would notice trailing... could maybe push it to 25 seconds.

My personal experience shows this formular to be pretty darn accurate. Now there will be some variability depending on your latitude, and what part of the sky you're pointed at (the sky will "move" less when pointed north and more when pointed east and west), and because I'm at 60 degrees N. latitude, I can do a bit longer exposures than someone at the equator.

In addition, the aurora can really rip across the sky as well. So, just as with running water, the aurora will blur, and you'll loose all of the detail and definition if you expose too long... heck, sometimes 10 seconds is too long if the aurora is really moving.

Hope that helps,

Mike

Yes, I had vaugely recalled that formula from somewhere in the dregs of my squishy melon, which is where the 12 minute thing came from. But there is a big difference between minutes, and seconds!!!

 

[jeroldharter]

Pentax 67 with the 45 mm lens (f2.8 I think) might work well for medium format.

 

[mikeklensch]

Pentax 67 with the 45 mm lens (f2.8 I think) might work well for medium format.

Thanks Jerold,

I came real close to getting the system you mention (and I still ponder the deals out there). But I ended up going with the Mamiya 645 system becuse of their line of fast lenses. I just wish there was something equivalent in LF.

Mike